I think it is very much in one's mind...every night when coming home from the office (been there at least 11 hours plus 45m ride in and ride home) I often feel like just going home and sometimes I do. Most of the time though I fight through it and go for a ride; at first I am thinking WTF am I doing out here?!?! Then about 15-20m into it I realize how happy I am that I did it.

I feel empty on the days when I "quit" and don't ride simply because of mental exhaustion...no excuse.