Friendly reminder: you don’t have to drink when you turn 21. If you have a family history of alcoholism, if you take medications that don’t mix well with alcohol (psych meds especially!!) or if you’re just not interested, that is your prerogative and you do not have to drink at any time if you are not so inclined. It’s not a coming of age obligation and if you don’t do it that’s fine.
Also, if you have religious objections to drinking: that is fine too. Whether you wish you could or not, that is a valid reason to not drink as well.