lol, I know exactly what you mean.  Its basically who is more stubborn.  I had a game recently where it was me and a toss.  He basically proxy gateway'd me on Desert Oasis, and rushed and killed my whole base.  While he was doing that I took my initial scouting scv that was idle in his base and just said fuck it, and built a barracks in there.  I actually finished it and built enough marines to kill him off, but he had a few pylons remaining.  Lifted off my buildings but had no minerals left.  
Basically had 6 marines, and he had like 4 zealots.  We met in the middle and he won the micro war, killing me and having 1 zealot remaining.  Since he couldn't take down my flying building, we were both sorta screwed.  I got pissy and told him I wasn't leaving, and he said the same.  Basically fast forward like 6 hours later, and I alt tabbed back and the fucker still hadn't left.  It was getting late, so I grudgingly gave in and quit.  That bastard.