You’ve heard the theories, you’ve seen his origin in Batman '89, Joker, and The Killing Joke. You may have heard the three joker theory from New 52’s Justice League. Who do you think the Clown Prince of Crime is in canon? And is he really insane?
My admittedly wild theory, he is really Thomas Wayne Jr. If you go into it assuming that Lincoln is a fake the Court of Owls created it works pretty well down to the white skin, high survival rate and obsession with Batman!
For the record, I like to call them Stephanie Browns instead of Spoilers!