College is like going to the gym. You pay a whole bunch of money for a gym membership, yet I know people who don't improve one bit from when they first set foot in that gym. In college you get out what you put in. If you think there are better ways to get drunk and have tons of sex then you might also think that there are better ways than signing up for fitness clubs to go socialize. However if you are looking to get in shape the fitness club is your only true option. Similarly if you are looking to be smart and well rounded (and well adjusted) College is your only answer.
College is NOT High School, they do not treat you like a baby and guide you allong. People can coast through college by taking easy classes, cramming, cheating, not showing up for class, etc. Why? because College expects YOU to do the work, not your Professor. They are not going to give you a bunch of homework you are expected to do by tomorrow and a bunch of tests to break up the material for you, they give you generally a midterm and a final (sometimes four if they are nice).
College is the only institution that teaches you to critically think about things because they rarely if ever teach you an opinion, they tend to give you books filled with facts and expect you to analyze said facts. Or they make you read two books from both sides of an argument and expect you to find some common ground. There you learn how to research, analyze, structure an argument, debate, discuss, solve and identify problems. These are things you cannot just get from reading a book.