Ask HN: What is a skill you developed without online tutorials?

Jerking it.

Programming. Back before the internet, we used things called 'reference books'. If you had a problem, you couldn't look it up on 'Stack Overflow' to cut'n'paste the solution, so you worked on that problem alongside the reference book until you learned how to fix the problem. Yes, it was slower than a cut'n'paste, but we learned a lot faster.