I didn't realize that aphantasia wasn't the way almost everyone experienced the world until I was 67.

In retrospect, it explains my career choice (which wasn't really a choice, it was simply what I was). Computer science, and in particular programming, is entirely verbal, with all thoughts in nothing but words (including artificial languages).

It perhaps also explains my aversion to GUI user interfaces.

I remember decades ago reading things like Einstein's ability to think in 4 dimensions, and not understanding what was so special about that; it's just like 3 dimensions, but one with an additional orthogonal direction. It simply never occurred to me that people could actually close their eyes and "see" three dimensional images.