Make it so there are few enough available tools and few enough people that they cannot properly use the tools to make a quick comeback, and reduce the population and communication enough to stifle the preservation and spread of knowledge.
Even then, the knowledge loss might not be as severe as you specified, as it is difficult to stamp out all knowledge of something completely. This is evidenced by actual history and knowledge that has been preserved for thousands of years.
To start, let's examine the two opposing requirements one at a time and specify a limit to either exceed or not surpass...
- human will not go extinct
Basically, all this means is that you need to limit the severity of the event. Almost anything can work as long as it is in moderation. Even a supernova would work as long as it was far enough to limit the damage to just the right amount.
- a catastrophe on the right scale that can wipe out the current civilization [...] will start to thrive again after some time has passed, but should not have any knowledge of the just-wiped-out civilization except some relics/artifacts and ruins, kind of like how we look at ancient civilizations
For this, you need to at least destroy enough of our infrastructure that nobody who wants to find the necessary tools can find them, and reduce the population enough that there are extremely few people left who know how to rebuild.
The first part, making sure there is no extinction, is the easy part: all you have to do as the author is say "but it was not so bad that humans went extinct." So I will concentrate on this second part. Also, since you could easily say "magic," or "aliens take over," or "virus makes people dumb," or "new supreme world ruler does it through his evil scheme," or similar, I won't bother with those author-fiat methods... if you use them then just say "just because."
To oversimplify the matter, you need 3 things to sustain the society and technology: tools, knowledge, and people.
To make the vast majority of objects that we take for granted, special tools are needed. I worded the previous sentence the way I did so that it can omit objects and tools that can be created by stone age technology. These special tools are often difficult to create and require special tools to create, which often require special tools to create... modern technology is built upon the technology of yester-year, which is built upon....
This might seem like a shaky tower of technology and make you wonder how we keep it going, but all it takes is 1 or 2 of these special tools to remain in the hands of someone who knows how to use it and many of the other tools can be rebuilt. All it takes is 1 wood or metal working mill or 1 lathe to remain in the hands of someone who knows how to use it (or figures out how to use it), and with that most of the other tools can be remade and modern technology cannot be forgotten. So the destruction of these tools needs to be complete enough that they are not available to anyone with the right skills.
To get to the point you are looking for, nobody with the knowledge of how to retain modern technology can be in a position to do so, and/or they cannot be in a position that allows them to pass that knowledge on.
Enough generations need to pass in this condition to thoroughly wreck their knowledge base. At the very least, there can be nobody left with the original knowledge; that is, enough time passed that all original survivors are gone. Further, it would probably require that everyone who could have talked to the original survivors are also gone; that is, originals gone and everyone they could have talked to is gone. If there is so much as a 10 year old kid who knows how to use a lathe or mill or who knows other useful tech-preserving information, and if that kid could live to 80 or 100, then that's 70 to 90 years before the kid is gone, and another 70 to 90 years before any 10 year old kids who he passed his knowledge to are gone. That is at least 150 to 200 years before all knowledge is third-hand knowledge and therefore of drastically reduced use. This also means that the vast majority of knowledge about civilized life and previous social structure is now gone too... people still remember that there used to be a France, a Russia, a United States of America, etc., but those concepts are something that the kids of that time don't care much about and have no use for.
All it takes is a group large enough and prosperous enough to support a couple of thinkers and allow them to devote their time to discovery and invention for a comeback to start happening. So, in order to thoroughly oppress their knowledge to the point you requested, the event needs to keep their living conditions terrible for quite a while so that preserving or relearning knowledge is not a priority.
Even after all this, assuming you keep it at all realistic, there will still be people passing on tales of times past, including vague descriptions of devices used such as giant synthetic bird vehicles and carriages that drive themselves, etc., and maybe even references to the long lost cultures and nations centuries or millennia away. It would be very difficult to stamp out this knowledge completely and entirely, but you asked for "like we look at ancient civilizations," so that's ok since the major civilizations of history were already known before we discovered their remains.
Saying that people are necessary sounds obvious, but it is not just a mere presence of people. For civilization and technology to thrive, a critical mass of people is required. That is, there has to be so many people that those people are able to share knowledge and ideas, to teach each other.
Another aspect of this is that, if there are enough initial survivors, then someone somewhere with the knowledge to preserve and rekindle technology is going to stumble upon the tools they need to do it.
So you need to have few enough survivors that they cannot create a free-flow of knowledge around the region, much less the world, and few enough that you don't have knowledgeable people finding the tools they need.
You will probably need to keep the population reduced to small pockets of people, most of whom don't travel much (to limit communication), for at least the first 150-200 years mentioned previously.
Something you need to keep in mind is that some people are very resourceful, some are very prepared, and some are both prepared and resourceful.
There are still people today, even in industrialized modern society, who are still practitioners of ancient technology, all the way back to stone age. There are people, and I know some of them, who can leave town with nothing (literally nothing... they could go naked if they had to) and feed themselves and start making old fashioned tools. Some of these people even have metal-working smelting and smithing knowledge. No matter what catastrophe happens, if it leaves even just a few of these people on the planet then you are unlikely to lose all social and technical capability, as they would immediately be right back up to at least stone age, possibly iron age capability.
There are also people who hoard stashes of food, resources, and knowledge. These people are often called "preppers". Both private groups of people and also national governments are prepped for major catastrophe. If you watch (and believe what they say) some of the prepper shows, some of those people have enough supplies stored to last well after they die of old age, and their supplies will continue to be used by future generations. Some of these include methods of renewable electric generation and tools for rebuilding after a catastrophe.
And if that weren't enough, there are literally books about rebuilding civilization after a catastrophe, condensing human knowledge into a form that can be readily used for that purpose. I happen to have two copies of such a book, which covers everything from agriculture to engines and electricity, and many things in between, including stepping stones to get back up to that level. It even includes many shortcut technologies that would allow us to skip over technologies that existed in the past and instead jump straight back into (or closer to) the end-game of nearly modern technology.
So you need to get rid of people skills, get rid of tools, and get rid of books. And not just the "how to rebuild civilization after a catastrophe" kind of books I just mentioned. For what you asked for, you need to get rid of all the history books, school books, and basically practically every other book that could talk about nations, technologies, or anything else you say should not be known. This is a tall order.
This, combined with the high availability of resources to be scavenged from the dead husk of the previous civilization means that this will be a difficult task and the event needs to be so very deadly and violent that it kills and destroys practically everyone and everything, leaving only a tiny remnant of humanity and without tools.
Also, the catastrophe needs to come as a surprise and happen swiftly so that people cannot prepare for it. If you know a year ahead of time, or maybe even just months, then the governments might push hard to put a "civilization jump-start package" space craft into orbit, either with a crew to bring it back down later or with an automated landing system. If individuals have time to prepare, they will do lots of things; hoarding resources, but possibly also burying them, putting some out to sea, flying some in planes or balloons...
So it needs to be swift and it needs to be a surprise. Even then, if more than just a few people survive and with a few tools, it will be hard to suppress the tech and social bounce back and to destroy the knowledge.
Real world example
There are historical examples of people cut off from others who have retained historical knowledge in one form or another, even if not very useful, for long periods of time. One of the better examples is probably the native Americans who thought that one day people would come across the water. They may not have had any realistic ideas about the true nature of where their legend came from, but it seems reasonable that their legend could have come from scraps of history passed down through the ages.
One of the things you will have to figure out how to deal with is the fact that people are actively trying to preserve their knowledge. We still find written records from thousands of years ago, and some cultures have traditional oral records which they teach to the next generation and take great pains to keep intact as much as possible. These records allow knowledge to skip ahead many generations, even thousands of years.
And now, what I consider to be the very best example, especially for you since it even involves a similar catastrophe...
There is a recorded event in Earth's history that, as recorded, is just about the worst catastrophe that could happen and leave humans to repopulate. This catastrophe is often referred to as the great flood, or Noah's flood.
The Abrahamic religions (Judaism, Islam, and Christianity being the most widely known and held Abrahamic religions) all stem from the person Abraham, who lived 10 generations after the catastrophe.
Whether or not you religiously believe the texts of the Abrahamic religions, there is no doubt that the written records that they kept are valuable and, so far for the events that we have found significant evidence to weigh it against, accurate accounts of history. Time and time again, when all the evidence is in for any given historic or archaeological inquiry, these records have been shown to be historically accurate and valuable tools for archaeology. And these written records indicate that there was a major world-wide flood which devastated the planet and left only a small handful of people alive. This major flood itself is still under debate as to whether or not it happened, but millions of people believe that it did.
Not only did humanity bounce back from that catastrophe, but we even have the catastrophic event itself documented, including its duration, the people that survived, how they survived, and an overview of the repopulation of the planet.
Further, we still have preserved knowledge of the people who lived before that catastrophe. In fact, we have names of people, at least 1 city, the occupations of some people, including an iron worker, and a very brief and high-level description of the overall state of affairs of humanity at that time: that it was bad, people were evil, and society was likely much worse than it is today.
Whether or not you believe this catastrophe account personally, you are looking for something believable. Millions of people do believe this account, meaning that it must be considered believable and therefor provides an excellent sample of a believable catastrophe.
Alternatively, if you are willing to change the landscape and living dynamic of the world, then you can work against the things I mentioned above by using your world-building against them.
For example, if the planet conditions are so harsh after the catastrophe that people are forced to spend all of their time farming with little yield just to eat enough to barely sustain themselves, and if all the forests were burned down (say, during a huge solar event) leaving little fuel to use for technological uses, that could greatly stagnate the progress and cause it to fizzle out.
Even so, I think the governmental massively prepared survival compounds would persevere, at least one of them. So at that point you probably need to combine all this with the idea someone else mentioned of a secondary event to kick them while they are down. But even then, if the story of Noah (and those with him) and the great flood is any indicator, the knowledge might not be as completely lost as you want.