The most accurate answer-- killing people-- he finds himself kind of reluctant to share. Everything about this world seems... gentle. Sharing with all and sundry that he spent all the time he can remember (which is not much at all) basically on a handler-directed murder-spree feels wrong and uncomfortable, even if he probably deserves the kind of ire that would net him.

So he gives the second-most accurate answer: "I don't know. I don't remember more than a day before I woke up in this world."