I do find revenge satisfying to think about, but when I've been in a position to actually get some sort of revenge on someone, I've realized that I couldn't do it. Daydreaming about cosmic justice, karma, etc can be fun, but when it comes down to actually being the instrument of that revenge, it's just not that great. At worst people can be evil, but generally they are just ignorant or misguided, and no amount of revenge will ever convince them that they're wrong or that they deserved it, so why bother?