See ya later!
This will be when the creature ages away, and prepare to plant their seed. For them, death equals to sleep. They will carefully prepare their grave, like preparing the bed before going to sleep. The rich may choose to be planted in fertile areas, to fasten their reincarnation.
Because they will have memories of their past self, the concept of friends and love surpasses generations. A 70-years old may kiss a 3-months old baby, whispering "Glad you make it!"
Grave (where the seed is planted) logically should be placed within their home, so the husband/wife can take care of the plant and guard it.
This when someone find out that their lover, or friend is actually dead. For good. This may be because of the unfortunate mutation that prevents the growth of the seed, or when the seed is actually pierced and irrecoverably damaged.
A funeral for a friend may involve burying the damaged seed and the cremated body in a grave prepared for the close friend, in hope that they will continue to live within their friend. This may be a plot point where the close friend gains part of the memory of their friend.
Surprisingly, for them "all things must end" holds true. There's sleep, and there's eternal slumber.