>I personally find that I’m often extroverted and sometimes introverted. I think it’s less helpful to think of this as a static character attribute and more of a mood.

I defined introversion as stable underlying trait that doesn't change regardless of how many social activities one participates in. I described it as similar to "right-handedness" being a stable trait regardless of new skills acquired with the left hand: https://news.ycombinator.com/item?id=27794484

However, if some people want to define "introvert" differently as only a temporary mood, I can't argue with that but I wish society came up with a different label that describes introversion-the-unchangeable-stable-trait.