A reader asked me: “Does your head literally tingle when you are learning something you find interesting?”
…It actually does! Sadly, the phenomenon is getting rare as I age, although I do still get it from time to time. It’s usually associated with learning that broadens in my horizons in some non-trivial way, a meaningful or especially interesting insight, that “light bulb going on” feeling. Sometimes it’s just sheer density of information, if I’m actually getting it. I never get that feeling when I feel stumped or overloaded; only when I think I’m successfully taking it in.