legalize legal drinking age from 18 to 21 for many reasonable reason

the legal drinking age is 21.. but for what reason why do they choose 21, when at 18 you become a legal adult. u can legally be put out homeless at 18 to be on your own and be a real man or woman but you cant walk into the tavern or by your own alcohol.. you can by your own cigarets at 18 fight in the war at the age of 18 you are your own being at the age of 18 accept for one thing holding that back and that's. some people are against it because they think that at that age you would be more to act out but from what i have seen the older ones act out more then the younger SIGN THIS PETITION IF YOU AGREE