Here’s my rough mental model around learning things in the world of computer programming:

1. Never heard of it before
2. Heard of it, but don’t know what it is
3. Know what it is conceptually, but not how it works
4. Know how it works, but never implemented it
5. Have implemented it, but just for fun, not in production
6. Implemented something in production
7. Applied concept creatively in a novel fashion (mastery)