For me it's more about "feeling" badly written code, as if it stinks and is unpleasant to look at,
and conversely enjoying nicely written one, and seeing its elegance and beauty.
Especially when I have to familiarize with code written by someone else, I usually start by "cleaning" it - small refactorings such as splitting overlong functions and simplifying expressions, that are trivial to prove as correct even without a deep knowledge of the code purpose.
Only when the code looks sufficiently clean and familiar, I start adding the requested new features
This is also how I have traditionally looked at new codebases. I don't necessarily actually clean it up (I dislike changing someones style unless it is completely necessary) but I build up a mental model similar to what you're outlining. It's been really interesting with these LLM coding tools. I may not disagree with the implementation in terms of logic (it just does what I've prompted it to do after all) but something about it will 'stink'. Amusingly this feeling is the true 'vibe' of 'vibe coding' to me.
I sometimes wonder if this is the result of experience/education (I'm not a compsci major) or if it's just a naturally different way to think about systems.
I also do this sort of restless refactoring. I find interacting with a new codebase is a kind of brain hack that (subjectively) helps me get up to speed faster.
Especially when I have to familiarize with code written by someone else, I usually start by "cleaning" it - small refactorings such as splitting overlong functions and simplifying expressions, that are trivial to prove as correct even without a deep knowledge of the code purpose.
Only when the code looks sufficiently clean and familiar, I start adding the requested new features