Marriage < casual sex...?

So a girl I went to church with just posted ultrasounds today. She is 18 and just got married in April. And I don't know if this applies to her, but knowing the environment she grew up in, it probably does.

I can almost understand raising your children with that wait-until-marriage attitude. Almost. Probably because I was raised that way. But I've noticed an awful lot of people who were taught that sex is between a husband and wife end up getting married awfully young. I want to know this: how do you think marriage is LESS life-changing than premarital sex? Youth is a time for you to be free to make mistakes, major in philosophy, go on dates with losers, get drunk and have sex with some douchebag frat boy, experiment with your hot roommate, try weed, and did I mention be free? Why would you ever tie yourself down this young, especially if all you're after is sex? It's like buying a house so you can bake a cake!

Now, I've just realized I've done none of these youthful things up there. Off to rectify this.