perversity of the human condition 

This is an explanation for when people do something that is different from what is thought normal or proper and totally unexpected for reasons which are completely unknown or thoroughly obscure.

Bob:- I saw John walk into the door.
Ben:- Why did he do that?
Bob:- I guess it is the perversity of the human condition.

perversity of the human condition by bevanp May 8, 2010