At the age of 18, any citizen of the United States of America can vote in local, state, and federal elections; smoke tobacco; operate a vehicle; and die in service for their country. That being said, any individual under the age of 21 cannot legally consume alcohol.
This forces individuals to learn to consume alcohol on their own (presumably with other alcohol-illiterate individuals) rather than being taught how to do so responsibly by a parental / guardian unit as is done with most other developmental phases of an individuals life.
Lowering the legal drinking age to 18 would allow individuals to have a sense of structure about drinking and respect for alcohol which can be instilled by those more familiar with the subject rather than a "trial by fire" approach.
Please sign if you agree