Assuming you’re an expert is a quick way to stunt your personal development.
This isn’t say you can’t appreciate having become more knowledgable in a subject — the difference being that knowledge is an infinite game. You can always seem to pursue more of it.
Expertise, on the other hand, presumes you know things exceptionally well. So well, that curiosity can safely retreat — after all, why would an expert need to be curious about something they apparently know deeply?
I think the great physicist Richard Feynman, who on many occasions would remark ‘I don’t know anything’, understood this well.
Assume no expertise.
Or rather, assume there’s always something to learn.
From this posture, you can be infinitely curious and learn many things that, as an “expert”, you like wouldn’t have.