I don't know how other people's imagination works, but I suspect when a spectrum person has good imagination and thinks they don't (I was like this myself), they don't realize that normal people's imagination also is built on real stuff, I think the difference is that we know it and they have a bigger subconscious and they are unaware more of their own mental processes.

I might be wrong.

Anyway, I have good imagination skills, I mean, normal people don't really imagine much do they? So why should spectrum people HAVE to if the can't?

It's all a bit confusing to me.