I witnessed that firsthand. Most of us had just gotten over 18, but not him. One of us ended up buying the beers for him, and he got just as drunk as us.

After we'd helped the poor guy into a taxi the news broke.

What he didn't know was that the bar had a policy of one beer per id card, so the guy how'd ended up buying for him had gotten alcohol-free beer for our underage mate in addition to the real beer for himself, not telling our classmate of course.

For the rest of that year he was known as Claus[1]...

[1]: https://www.clausthaler.com/