I learned about Aphantasia about eight months ago, and it really sent me for a trip. I have no problems visualizing in my mind and sometimes can get lost in it, to me that’s what daydreaming is.

I discussed it with some of my friends, and it seems to exist on a spectrum. The most different from me was one friend who had to really focus to visualize in his mind, and even then he could only do so in black and white.

I find it absolutely fascinating that the human experience can vary so greatly at such a fundamental level, yet it doesn't manifest in ways that are obvious to others, and everyone thinks that their form of thinking is a common shared experience so they don't even bother to talk about it.