For instance: age of sexual consent, age for legally drinking alcohol, age for driving, age for voting, age for participating in pornography
Depending on the place, each of those requires a different minimum age. Why is that? Are some activities “more adult” than others? Using USA as an example: legal drinking age is 21, legal driving age is 16, age of consent varies between 16-18.
Not asking about different countries/states having different ages, but any single place having different ages for different adult activities
I will say that in my home my parents also had healthy relationships with alcohol, when I say I have some family history it’s not like I grew up surrounded by drunks, I have a few aunts and uncles and such who I’d call borderline or functional alcoholics, my grandmother was an alcoholic but sobered up long before I came around, etc. There were enough good cautionary tales around, but also plenty of good role models that did a good job of setting me on a good path to be a responsible drinker.
Also, my parents are almost a caricature of responsible, boring suburbanites who did a good job of teaching me the value of a dollar and all of that boring crap that my fellow millennials complain about not learning in school, so while I very much enjoy drinking, my wallet would never let me become an alcoholic. Even the cheap stuff is too damn expensive, and life is too short to drink shitty beer.