Or here's a crazy thought....Why the #$%^ should the governmet have any right at all to say when I can, and cannot drink?
Have an alcohol related motor vehicle accident and lose your medicare benefits for that treatment. Kill or injure someone while under the influence? Go to jail. These are laws I can get behind...but an arbitrary age where I am "allowed" to drink? Quite frankly, piss off.
The government tells you when you can do a lot of things. They tell you when you can drive a car by yourself, when you can officially post your opinion on the runnings of government, when you can buy cigarettes, when you can consent to sex, when you can be held accountable for certain crimes, and so on.
To some extent, they do have an interest in that. Up to a point, it's to be expected that a child will make poor, uninformed, inexperienced, irresponsible decisions, and that a parent or guardian has a right to make decisions on the child's behalf because of that (and that if the parent/guardian also makes poor decisions for the child, the government can step in). The government has arbitrarily decided that eighteen years outside of the womb is the point at which a child can start making his/her own decisions (or, in the case of drinking, 21). You're just pissed because you're not there yet.
The argument isn't whether or not the government has the right to restrict you from doing things until you have the physical and mental capacity to do them without killing people. The argument is why the government has chosen the relatively advanced age of 21 for drinking when the age for just about everything else is 18.
In terms of anecdata, I spent a semester in Reading, England, and one thing I noticed about the first-years was that they got just as pissed as the freshmen did back home at UGA. The difference was that in England, where the drinking age was 18, they were more likely to take a cab home or call the hall for a ride when they were too drunk to get home on their own, and they were more likely to seek medical attention when they'd had way too much, because they weren't afraid of being caught drinking underage.
Of course, we also had three bars in the Student Union and one in our residence hall, so it's not like they had to stumble too far to get home anyway.