When I was growing up, alcohol was readily accessible. My parents were the partying type and parties were a regular occurrence. I think I had my first beer by age 3-4, first hard liquor drink around 4-5. In both cases, my young tongue didn't appreciate the sharpness of it and to this day I'm not a beer drinker and don't care for most of the hard stuff. I've never been drunk either. I do enjoy a glass of wine or mixed drink with dinner occasionally. I also accidentally learned in college that a glass of wine actually improved studying after my study group had been to a wine tasting for an industrial microbiology course. We were all shocked by how much more enjoyable the study session had been AND how much better retention of the info was the next day.
The USA's idea of alcohol being outright forbidden until age 21 is a recipe for disaster. You don't ban power tools, weapons, cars until a certain age then expect the person to magically be able to handle them when they turn a certain age, but that's exactly what we do with alcohol. Children need to be exposed and trained on how to handle situations. Drinking responsibly isn't something you'll learn from a book.
To give you an idea how how absurd and paranoid our laws are, in Florida it's illegal for a teen to even touch a bottle of alcohol...even if their parents give it to them... BUT they can if their employer gives it to them (still can't drink it though).
Literally, "Hey son, can you go get me a beer from the fridge" is punishable for up to 12 months in jail for the son who never even opened the bottle, matching penalty for the parent who "allowed" this offense to occur. Prohibition is alive & well...