Are there any quick wins that 30 ~ 60 minutes of intense concentration can generate?
For example an average person, if focused, can learn to read (but not understand) Korean decently in under an hour.
A person can also learn a few guitar chords and possibly play a carefully-chosen song in that time.
But those aren't valuable skills in themselves.
Do you know of any simple + valuable wins in your area of interest?
("valuable" intentionally left vague)