Your friend is angry, and likely at himself, even if he won't admit it. I've been that way too, which is probably why this comment from Jean-Luc Picard (TNG: S04E12) struck a chord with me:

"I think when one has been angry for a very long time, one gets used to it. And it becomes comfortable, like old leather. And, finally, it becomes so familiar that one can't ever remember feeling any other way."