Yes, I do have a map of the code in my head of any code base I work on. I know where most of the files are of the main code paths and if you describe the symptoms of a bug I can often tell you the method or even the line that's probably causing it if it's a 'hot' path.

Isn't that what we mean by 'learning' a codebase? I know my ability is supercharged compared to most devs, but most colleagues have it to some extent and I've met some devs with an even more impressive ability for it than me so it's not like I'm a magic unicorn. Ironically, I have a terrible memory for a lot of other things, especially 'facts'.

You can sorta make a crappy version of that for AI agents with agent files and skills.