[brudgers]

The mistake I often make when trying to learn anything is assuming that what I already know justifies skipping the introduction of the basics. Essentially, it's an indiscipline. I look at the material and think, I know that and don't actually do the exercise.

Anyway, my go to recommendation for functional programming is How to Design Programs with the caveat that it is really easy to fall into the trap I describe.

Good luck.