What's one thing school taught you that was completely useless, but now you feel it was worth it ?

Memorizing poems.

Hated every second of it as a kid. Felt like a complete waste of time.

But years later, during some of my lowest moments, those exact lines randomly came back to me. And they actually helped.

Funny how that works.

now my_qualifications is PT class teacher. So I want to understand what are the things we rolled our eyes at but quietly absorbed.