Elevator Anger

I shared an elevator with a man wearing running clothes. I was on the top floor, and he stayed in the elevator when it picked me up and rode all the way to the bottom floor. The elevator stopped at each of the nine floors on the way down, and he became visibly angrier every time that the elevator stopped. Since he stayed in when the elevator opened at the top before going down, I'd guess that he was mad at himself for getting into a car going up instead of going down. That said, why didn't he just take the stairs since he was already prepared to workout?