me_irl

The only meaningful use of the introvert/extrovert dichotomy in my experience is just that extroverts charge their batteries in social situations,

It makes a bit more sense than of the original reinterpretation but in the original Jungian sense, the dichotomy is very simple and also precise: Whether a judgement function (some hardware in your mind) concerns itself with subjective (introverted) or objective (extraverted) data, whether it looks at inside or outside. And yes it's extra, not extro.

The actual difference between people with dominant introverted vs. extraverted function is experience-then-learn vs. learn-then-experience. To draw a caricature: You won't get an extravert to calculate a ball's velocity before they've kicked it, and you won't get an introvert to kick a ball before they've calculated what will happen. Likewise, plenty of extraverts out there all alone, climbing a mountain or something, and introverts at busy chess tournaments: It's not about sociability.

Other psychologists then took the terms and tacked them onto their own theories, which is where the popular drive-centric understanding is coming from. In particular from Eysenk I think.