After 31. ...h4??
You should be the first to admit that to resign even though you should lose in two moves doesn't mean that you will lose 
Good for him. Play on, sir!
P.S. - Maybe offering a draw rather than asking for his/her surrender, considering the circumstances of your soon-to-be victory, wouldn't have been such a bad idea on move 47. Just a thought. Maybe not a reasonable thought 
OK, do you know what is the strongest piece on the board? No, not the most valueable (everyone knows that's the king) but the strongest. Newbs and weaker players will say "Queen!". But the chess masters will disagree and say "Pawn!" This game perfectly demonstrates why the latter are right...