Carmack was of the moment. His ruling force was focus.....

“ Carmack was of the moment. His ruling force was focus. Time existed for him not in some promising future or sentimental past but in the present condition, the intricate web ol problems and solutions, imagination and code. He kept nothing from the past–no pictures, no records, no games, no computer disks. He didn’t even save copies of his first games, Wraith and Shadowforge. There was no yearbook to remind of his time at Shadowforge. There was no yearbook to remind of his time at school, no magazine copies of his early publications. He kept nothing but what he needed at the time. His bedroom consisted of a lamp, a pillow, a blanket, and a stack of books. There was no mattress. All he brought with him from home was a cat named Mitzi (a gift from his stepfamily) with a mean streak and a reckless bladder. ”

David Kushner

From : Masters of Doom: How Two Guys Created an Empire and Transformed Pop Culture