My hair doesn't curl at all. I'm alright with this. I'm just curious, though - would it straighten?

My hair is really thick, and healthy. I’ve heard that the more healthy you are, the harder it’ll be for your hair to curl. Well, I’m alright with no curly hair. I’m not sure I would like curly hair. But I’m curious – would it straighten? It has just enough wave that straightening it would show. But I would think that since it doesn’t curl (and, believe me, I’ve tried everything), would it straighten?