Everything in high school is irrelevant. Thing is, people typically have to graduate before they can appreciate the true irrelevance of it all. I often think that my life only really began when I accepted my high school diploma. Four years from now, I'll probably say the same thing, except about accepting my college diploma.
From my own college experience, sort of true.
You could take a lot of the same attitudes about getting laid before the end of high school and apply it to getting engaged before the end of college. There is kind of this feeling that if you don't get engaged or don't have a serious romantic relationship while in college you're a loser. Sure, rarely anybody outright says this, but peer pressure is pretty damning. If there is one thing that college has taught me it is that the value of marriage is highly overrated amongst young people. I mean, these kids are like 23 f***ing years old man! They got all the years in the world to be breeders, at least try to enjoy being single while you can.
Also, there is this expectation that you should know what you're going to be doing with the rest of your life when you graduate. Wrongo, you only know what your major is going to be. A large number of college graduates inevitably end up doing a professional job in a field different from their own (like Accounting Majors becoming Museum Curators). Keep in mind, also the emphasis on staying the hell away from Liberal Arts because "people with Liberal Arts degrees are low wage f****ts who'll spend their first few years working at Wally World!" With so many kids who possibly could've been Literature or History majors who have had so many adult figures and contemporaries drill in the idea that following their dreams would be akin to a low wage death sentence and thus "settle" for "higher paying" degrees, is it any wonder that a lot of grads now days don't have a funking clue about what they want to do with life?
SO yes, arguably your life really does begin after college. Sure, in college you had freedom from parent figures or what not, but you had the slavery of education upon you. You had to go to class, you had to take tests and other sh*t. If you fail out of college, your life begins even earlier. Not being in the state of education is the freest feeling anybody can have. Having a professional college degree may not be a magic key to a professional job (you have to work at it, like I am), but once you have it you will be thankful you do have it. And if you don't know what you want to do with your life after you graduate that isn't a problem as long as you kind of have an idea of how you want to start out. Just find a job field you feel comfortable working in and send in your resumes and cover letters. You got the rest of your life to find out what you want to do with it, college is mostly just insurance that makes finding one easier (if you will).
So remember mostly, that if you graduate and you don't know what you want to do with your life it is not wasted. Rather, you can use the experience you do have to help you gather more experience that will (hopefully) guide you towards your path in life. Unless of course, you like living with your parents

, which is a fate I consider worse than death.
NOTE: I really like my parents. They are the coolest parents anybody could have, but the idea of being a leach for the rest of my life is a scary existence. So don't take this as a "Mechaman hates his parents" comment at the end.