Do you have a hand that seems to be your "hex hand?"
Do you have a hand that you always seem to lose with and/or get beaten with? Mine is A9. I try not to play it at all, but in those late position, desperately short stacked situations it's certainly worth shoving in with.
I almost always lose with this hand... or in an all-in situation against someone else holding A9, I get beat by it. It doesn't seem to matter whether it starts out as a favorite or not.
I was all in tonight with A9 twice. I was *SHOCKED* the first time to end up making quad aces... plus a 9 on the river, as if I needed it. I'm sure that sucked up all my A9 luck for the rest of my life, though, and I was later knocked out of the tournament with another blasted A9. It was ahead before the flop but, alas, not after.