I always assumed that "Personal Development for Smart People" was intended to be a play on the "for Dummies" book series.
At any rate, if I read Dostoyevsky, I'll enrich my mind. (Maybe, actually I have tried to read Dostoyevsky and rather suffered an implosion, but maybe I just don't resonate with it.
) If I read A Course in Miracles, or travel to the streets of India, or whatever, I'll enrich my mind. Maybe one day I'll do some of these things, and in the meantime I'll do other things to enrich my mind.
I'm probably not the only person here with this approach, I imagine ...