What’s something you made it all the way into your 30s without learning?

I'll go first. I don't understand internet. And I don't mean, how it works. Yeah I don't really understand that either. But I've never had to order it, set it up from scratch. I don't know what a good up and download speed is. I don't know the difference between dsl or cable. I don't know the difference between a modem and a gateway. Idk how many gigs I need. 5G what's that mean? It was always done for me. It feels like something I should understand but I honestly just do not care.

But, that made me wonder, what is some common knowledge or know how you just never developed?