Luck?

You may think I'm unlucky,

but I will always be the opposite of what you expect.

Think 13 is unlucky? I was born on the thirteenth. It's my lucky number, and my favorite one at that.

You afraid to spill salt? I'll make as many messes as I can to prove that I was somewhere, that I exist.

Terrified of going under ladders? I'll be the one underneath your ladder, supporting you wherever you go, and if you fall then I'll be the one who's in pain?

I am Jinx; I cast curses unto myself so you can be happy.