I've got two. I call em the time bomb and the equivalent exchange.
Time bomb; No matter what I do or say or how nice I am to people, they always get stick of me and break all contact, generally within a month and the longest things ever last is three months. The few people I've known for a good length of time are very distant. I don't much like people in the first place, but this makes it completely impossible for me to ever have real friends, let alone lovers, and I'll forever be alone as a result.
Equivalent exchange; I can't be too happy or have things going too well for me, because if I do life will fuck me over soon enough in an amount equal to or greater than how good everything was. They wont let me starve and suffer, but they wont let me be happy. I'm forever forced to remain in a neutral purgatory like state, or pay the price if things improve.