On aphantasia—no mind’s eye. The wildest part is that you’d never know unless you asked:

Aphantasia and hyperphantasia are not disorders. People at either extreme of the spectrum don’t have problems navigating the world. Aphantasics are often fine at describing things, Bartolomeo said. When he’s asked them how they can visually describe objects or people from their memories when they lack mental images, they respond: “I just know,” he said.