I don’t understand the question. Are you implying someone cannot know how to do something in a particular codebase unless they’ve already done it on that same codebase?
To be a good performance optimize yes,you need to have done it a few times to be good at it and have acquired not just the skill but the discipline and taste.
More than having done it a few times though, what is more important is to have thrived in a space that is welcoming of intellectual curiosity and play in matters of performance. That's how one becomes good at it.
