"Heinlein's dangerous. Much more dangerous than Potter. I find ideas popping up all the time that I can trace back to Heinlein... mostly about learning and the virtues of being able to do anything you set your mind to."
Sigh. The point of that (true) story is that the books from which I acquired moral precepts that I later acted on in the real world were "just fiction."
Uh. Ok. Well, I guess I can see your point.
There's a difference between learning ideas from books, and learning practices from books. I used to read a lot of Robin Cook novels but I never tried to remove my sister's appendix. I like the Spider-man movies but I don't try to shoot webs from my arms.