How can I know that having / not having aphantasia is a real thing? Our bodies are otherwise so similar that it would be surprising if our brains were wildly di

How can I know that having / not having aphantasia is a real thing? Our bodies are otherwise so similar that it would be surprising if our brains were wildly different in operation. If people are able to "see" their thoughts in the same way as they see something with their eyes, wouldn't it be difficult to think about a cat while driving a car, because the cat would be in your visual field? Or is the "mind's eye" somewhere else, if so where do you feel it is? If I think about a cat, it's kind of a concept. If I try to think harder, I can sort of trace its tail and fur and ears, but it seems very different to actually seeing one. Just as when I imagine a taste, it's very different from actually tasting something (otherwise I would just imagine food all day without actually eating as much). The only time when these seem the same is when dreaming.