If you could know one answer to any unsolved mystery, something we just don’t know the truth about, which mystery would it be?

Okay, I'm going to give a couple of funny answers and then a couple of serious ones: Funny answer 01: Where... where do all of these freakin' Tupperware lids come from? Are they somehow made from the socks that disappear in the dryer? Funny answer 02: What happens to all of the socks that go missing in the laundry? Real answer 01: Are we alone in the universe, or is there other sentient life out there somewhere? Real answer 02: Is the supernatural real? Is there some basis for all of the stories of ghosts, psychic powers, unexplained phenomenon, etc.?