There's a caveat though: through just reading, it's easy to fall into the illusion that you learned anything. Maybe for some this is enough, but I'd wager that for vast majority of people (myself included), to internalize some idea even on the most basic level, you have to do something along the lines of:
- rehearse it after a time, or
- try to derive it by yourself (applies to e.g. math and physics), or
- explain in your own words (whether by teaching someone, or just writing a blog post), or
- code a working demo of it
Basically, you have to apply the idea somehow to actually learn it.
I agree, but I don't think there's a difference whether the initial idea is consumed as fiction or non-fiction.
And it's certainly true that writers of hard-to-grasp ideas often use both - fictional examples in non-fiction books, historical examples and exposition in fiction books.
- rehearse it after a time, or
- try to derive it by yourself (applies to e.g. math and physics), or
- explain in your own words (whether by teaching someone, or just writing a blog post), or
- code a working demo of it
Basically, you have to apply the idea somehow to actually learn it.