I wish I could give a hug to the me of a year ago.
When you’ve been working on a large codebase for a long time, it’s common to forget bits of it. You create a mental model which represents approximately what a class or a file or a function does, and then throw away your memory of how the inside of the class actually works, to make mental space for other things.
This is a companion discussion topic for the original entry at https://blog.mmorpgtycoon.com/post/letter_from_me/