The thing we most take for granted is, ourselves. We notice that we come into existence before we know it. And, in fact, if you hadn't noticed it, thoughts arise before we know it, and our imaginings surface and rise into daydreams -- before we know it.
And the will, deliberately, to imagine also arises before we know it, as a growing impulse that we may perceive closer and closer to its root, as an intensifying of attention.
So, I think everyone's imagination is an arising from an innate place to go into places -- the places we think to look and their neighboring places.
It's just that some people's memories have a stronger grip than others', and so complicate and garble the arising imaginary newness, rather than allow it to arise in a more streamlined and more integrated (and so pristine) form.