A quick follow-up post to this one:
There are, it’s worth adding, different kinds of imagination. I know a professor who has an excellent scientific imagination, but a poor fictional one: he can imagine all sorts of things that might be true, but finds it hard to enjoy fiction that strays too far into what just isn’t. My grandfather was rather like this: a very bright and intellectually curious man who couldn’t enjoy books in which animals talked.
Of course, this doesn’t necessarily reflect a lack of imagination. Maybe my grandfather was perfectly capable of imagining a world where animals talk, but just didn’t especially like doing so. Perhaps this is true of people who don’t get thought experiments. I suspect, however, that there’s a failure in both cases to understand the game you’re being asked to play.