Yeah it's worked really well I recommend it! One other note: the company I work at won the startup lottery and has grown very fast for the last 5 years, which allowed me to see multiple company stages and roles. I break down my notes by what I've learned by company stage and role as well (eg right now when I learn something about Marketing, it goes into the Marketing section of my Growth Stage "chapter"). My doc is ~50 pages so far and I honestly view it as a secret part of my resume at this point.

I also keep a list of blog/Quora/HN/Reddit posts that I've found helpful and timeless in a separate doc. This second doc is also useful, but a mess :-)