Forgive me if I sound ageist here, but the majority of teenagers/early 20-somethings have no idea who is or is not the right person. Especially if that's the only person you've ever dated. I don't understand the rush to get that piece of paper that says you're married. You're together, who cares if you have it or not. The only real pertinent benefit for most people would be health insurance from spouse or *maybe* lower taxes. Oh, and spousal benefits from your armed forces spouse (but I find that is more often a "scam" than not).
My wife's cousin got married damn young. Bought a home *just* before he got married, wife never worked a day, he put her through school. Just as she's about to finish, she starts cheating on him, leaves him, gets a divorce, and he has to pay her off in the high five digits just so he's not forced to sell his home... that she never paid a dime into... and it wasn't like she was staying home taking care of the kids (they had none). Had they not rushed into marriage, and just dated longer, he'd have had more time to see what a crazy psycho bitch she was.
Half as many people get divorced each year as get married. It's not some sacred thing apparently. What's the rush? /shrug
(PS I never wanted to be in my mid 30s starting a family either, but it took me that long to find the woman I was willing to spend my life with. I'm glad you found that much sooner, we can't all be that lucky)