Necessary? They aren't to get through college, there have been cases (albiet rare) of people entirely graduating before ever turning 18. There are certainly w

Necessary? They aren't to get through college, there have been cases (albiet rare) of people entirely graduating before ever turning 18. There are certainly ways of dealing with it. It does however create a great many inconveniences that simply vanish the day you turn 18. For instance, if your finances are such that you need a job (as mine were), there are many employers that will not even consider someone below 18. In most places you cannot own a car. Few landlords will let you take out a lease in your name. Most places will not extend you credit without a cosigner. All of this can be overcome, and if you are planning on staying at home with your parents at least initially then dealing with it is quite easy. But if you are planning to move out, it is still a series of challenges/inconveniences that simply vanish the day you turn 18.