At 17, you usually have a sheltered view of the world. You usually don't have much experience when it comes to relationships or the real world in general. I went to comm. college for awhile and I was certainly not the only one who was single. Yes, I had a lot of people in different classes who were married, but more of my classmates were single. When I transferred to Eastern Michigan, I found more and more people to be single, even at older ages. Yes, I now have quite a few classmates who have gotten married or are getting married, but there a good number of us who are still single.
I wasn't ready to get married at a young age, and neither were a lot of my friends. I'm 24 and am still not 100% ready for that commitment. A lot of my close sorority friends are single. We enjoy our time in college. We may be looking for that long term relationship, but at the same time we're looking to enjoy ourselves. I just got out of a 4 1/2 year relationship- everyone though we were going to get married. We started dating when we were 20 and we've changed so much since then that our relationship wasn't working any longer. Your 20's are the time to grow and find yourself as a person, in my opinion. Get into the real world first, then think about marriage.
To be 17 and think you're ready for marriage, in my opinion, you're nuts. You probably haven't lived on your own, tried to support yourself, or even had a real job. More power to you if you want to get married at such a young age, but it's a lot more work than it seems.