What do you "see" in your mind's eye? Is it as real as looking at a photo? Or do you not see any images at all? It turns out there are 3-5% of the population who don't have the ability to form images in their heads. It's a condition called "Imagination blindness" or Aphantasia, and it was only recently discovered.
Along with Aphantasia is the opposite end of the spectrum, Hyperphantasia, where the mind's eye is so vivid, it's hard to distinguish between what's real and what's imagination.
It opens up a lot of questions about how we see and perceive our world.