I think curses are way fake.
I believe in coincidences. You want something bad to happen to someone so many times and it actually happens. Well it would have anyway if you wished it or not. Its just you remember saying a "curse" to them since it happend relatively close to when you stated it.
But now, I think they're real....my family is from Louisianna and my dad always used to tell me crazy stories about my great grandparents and how Voodoo was a big thing in our family.
i remember watching some thing about voodoo on the discovery channel and they said that sometimes when witches curse people they believe theyre gonna die so much that their so afraid and their heart goes so fast that they actually do die from freight