"People talk too much about moral and immoral, right and wrong, good and evil. I do what I do, I k-k-kill. It is simply my nature, my raison d'etre."
"I did warn you not to trust me."
— Petyr "Littlefinger" Baelish, A Game of Thrones
"You will not understand this," she said, "and it is even right that you will not understand this, given your profession, but I will try to explain. This is what I do. Worlds are made to be pressed for their wine, cities taste of fruit when I bite them open. I cannot let go of my conquests."
Effigy Nights by Yoon Ha Lee.
If you asked Old Garrett why he stole, he'd answer "'cause I need to pay rent, and it's the only thing I'm good at, so shut up and let go of your wallet." New Garrett would (and indeed does) give the answer "Because it's what I do." No, Garrett, it's what you are currently doing.
"Hey, Yahtzee, why are you kicking New Garrett in the stomach?"
Jade: You lied to me! You used me!
Rick Flag: Seriously, what the hell is wrong with you people?
Harley Quinn: We're bad guys, it's what we do.