Many years back, I was thinking a lot about the idea that people could have different experiences of the world without realizing it, just thinking their experiences are normal, so I decided to write down a bunch of things I had thought of as normal (or kind of normal) but later wondered if they actually were (and other things related to the topics I wrote about). For things here where I am normal, at least someone has now said it explicitly; for things where I'm unusual, I've documented that there is at least one person with that trait.