I'm wondering how things would have happened differently if it was perpetually raining over the entire surface of the earth. How would life have evolved differently? How would civilisation be different? Would technological progress be hampered? Would it be impossible to construct buildings? Would it prevent us from waging war?
Constraints: The water doesn't just come from nowhere. The usual rain, flow to the ocean, evaporate, rain, flow to the ocean, evaporate cycle is still going on, it's just that it's sped up by 1000000 times such that it is perpetually raining. In this way there shouldn't be a global flood (although I'm open to this happening if there is some other reason)