i had a grudge motivate me once in a freeroll. someone cooked me a NICE dinner...i played the first 15 mins of a freeroll, i think i doubled up, then dinner was ready and i sat out. i came back to see the blinds are pretty big and i have 300 chips left, sweet, AQ on the BB...i call the raise of the guy who's got the biggest stack at the table...had only been back long enough to see he's playing every hand and just getting lucky, very agg play. he had a suited AJ, i won with trip Q's, cool. he said "lol, f a g". no prob. suited 78 on the sb, he raises mid pos again of course, i go ahead and call with the shove. he's got 3J or something and i get a pair of 7's and win. he said "fn idiot, you won't last long, i got you", then he said "lol"...then someone else gets knocked out, the table collapses. i wouldn't have cared but i thought "i have got to stick around long enough to see someone knock this guy out"
needless to say, i pick up a few more wins, of course i'm still shortstacked, but its getting late and oh my...i end up at the same table as him, he has a little bit bigger stack than he had but not much bigger, an hour later. i doubled up off him again! then he got in a re-raise war with someone with a bigger stack...only he had a Q4(or5) and went all in and lost to whatever the other guy had and he said "omg you fn donk!" and you know what i said "lol"...i couldn't resist. he said "lol???" then he stuck around and cussed me for a few mins at which point i just kept my mouth shut. no i didn't finish in the money, no, i didn't last much longer...but he was my motivation to stick around in a tourney i didn't even care about
grudges are allowed, just, don't let them affect how you play. play your game, if it makes you look timid, you'll get them, or someone else will eventually. i've noticed at times while i'm getting picked on by someone, thinking i'm going to fold every blind to them, when it seems my high card is 5 every time they do it...they seem to forget someone else all ready hopped in the hand and it comes back to bite them...don't pick fights with 3 ppl just because the 1 jerk you want is in the mix