In a post on his blog Michael Stivala looks back on his own code written a year ago. Because he learned a lot of stuff in a year time, he seems a lot of room for improvement.

As I’m picking up the codebase ahead of this Summer’s updates, I can’t help but review and refactor the existing code. It’s interesting to dissect previous design decisions. Also, I’ve learnt so much in the last year that it’s only natural for me to want to bring the standard of an older project up a bit.

https://michaelstivala.com/things-i-used-to-do-that-arent-cool-now/ If you look at your own code from a year (or longer ago) and think "this is allright, I can't improve on this", chances are you're not learning enough.