Have you ever learned a technical topic successfully from eBook?

I have learned some proper welding technics using some book from 1950s which I have found on torrents. Before I found this book I used to watch Youtube, ask my friends with welding skills and all of those worked not that good. Maybe my previous practical tinkering with a welding kit did some work in teaching me welding, but the book has few extremely useful tables with some data kind of what parameters to apply in this or that thickness of metal, position of seam and kind of joint. I love learning from ancient books if I know that nothing has changed in the industry.

I got hired as an Elixir dev with zero Elixir experience (They knew this before they hired me). I spent a week learning how to think in Elixir, and how to code.

This was all done with a pen some paper and a couple books my new boss recommended (sent me some pdf's too)

It wasn't a full set of knowledge, but I did merge code in the first day on the job, so I could at least operate in the language.

Yes. Recently, I bought an ebook on Go and it is excellent in walking you through building a full CRUD App and API with best practices.