Do curses work or exist?

I believe curses or hexes can work if you believe in them, so can anything! If you believe the sky is green you're going to see it as green, the mind is a complex thing and we can manifest what we believe as it can also depend on our mindset, if your a positive person, well grounded, and think rationally then curses do not work, I personally do not believe in curses or hexes...