I learn how to play piano and music theory from scratch. Before I played bass guitar in a nu metal band but didn't know how to read music. I essentially "faked it".
There's also musings on what musicianship, music and art is. Oh, and I'm creating a brand new music genre: hymns + djent metal = Dhymn.
Readwise.io user here, and I love it. Readwise helps me remember what I read (not just books, but articles too). I get sent a daily email with three excerpts/highlights and it quickly refreshes my memory. Books seem like a better investment for me now because I'm not just forgetting them.
BTW, you can choose as many or few excerpts as you want, and what books / articles as well.
If the good folks at Readwise are reading this comment: I'd love to see an Android app with OCR capability. I read "dead tree" versions of books from time-to-time and want to save those highlights.
I use both daily. I use G Keep for temporary notes of any kind, and Evernote for posting on my blog (via Postach.io) and anything I'll want to keep long-term.