Do you personally have or believe in any hypothesis explaining why we are gay instead of straight?

I really hope that in my lifetime, I live long enough to see the day when I know the answer and the answer to that question is figured out. I want to know why I am different, why am I the way I am. What made it.

I actually only half want to know, satisfying my curiosity and the good old big question "Why am I here?". The other half I don't think it's a good idea, because if there's actually a concrete reason, people and especially homophobic people would try to "cure" gayness