It does still raise the question in my mind of "how expert" you need to be.
I was very careful in my original description to talk about "diverse interests that I've pursued to a level I would say is beyond an apprenticeship but has not yet reached (and will likely never reach) mastery."
I still think "expert" gets a little too close to "mastery" for me but I understand that might be relative.
I'm highly reluctant to attribute the term "expert" to myself in the context of any of my interests, whether linguistics or Greek or general relativity or music theory.
I would say I'm at most at grad-student level in each of those. I don't think that earns me the "expert" badge.