Thanks for that reference. Having read Outliers years ago, Peak sounds like a useful follow-on and the concept of “deliberate practice” makes sense to me.

I’ve been learning guitar over the past couple of years and I still struggle with many aspects (with good rhythm and timing being the most difficult). I’m mostly self-taught (justinguitar.com) but have recently started a music class to get feedback on my playing. My wife is also learning Mandarin and it sounds like the kind of book that she’d be interested in.