2. Pain is the most effective way to learn.
I was a 90s kid, still just young enough to have my parents tell me to go get out a paper dictionary when I asked "what does this word mean?" It's amazing how much better it "sticks" when you have to stop, get up, open a book, and find the entry.
With a minimal vim setup, I find that I just know Linux, the language intricacies, and the codebase better than my coworkers – not because I'm smarter but because I have to manually look up things I don't know. It's slower in the moment but over time it is much, much faster.
For the same reason, I never copy/paste code that I could not have written from memory.