Like everyone else pretty much said, it really depends on the person. There's just some people who aren't mature enough to handle it.
Me, personally, I don't plan on getting married until I'm in my late 20's at the earliest. I'm going to go to college for 6 years, do some of the traveling that I've always wanted to do, then settle down in Chicago and get a job at a newspaper.
When the right person comes along, it's just another wonderful gift from God. If they're 'the one,' then they won't be going anywhere, so you could hold off on it if you wanted and do the things you want to do first. My parents always say that being married kind of grounds you, because you have a respnsibility to the other person, so you can't just go off and be spontaneous without them.
Whatever you decide, I'll be praying for you.
Much love,
~Sammy