There is an near-infinite expanse of stuff to learn in every direction you look. Human knowledge and culture is a fractal, even when you think you know everything about a subject there’s always more to be surprised by or to do.

I’ve recently been reading up on cryptography. That part of software engineering alone can take years to catch up with the latest post-quantum developments.

There is also always some basic shit which you forget with time. I need to re-read The Art of Computer Programming at some point.