I definitely retain it. In the case of the gardening - I pretty much immediately go outside and practice it.

In other words, how I get the info doesn’t matter (book, video, llm) because I’m locking in the skill by doing the thing in the garden.

And sometimes it is kinda wrong/suboptimal, but not more than e.g. asking a friend for gardening tips. Usually this is based on lack of context, like eg im growing cherry tomatoes and the AI assumed I had full size tomatoes