Discovered today that one of the most formative books of my childhood, Math For Smarty Pants (1983), is available as a full PDF online:

https://arvindguptatoys.com/arvindgupta/mathpants.pdf

It's not a super well known book, though I bet there are plenty of Fediverse nerds who loved it as much as I did. The book was full of cool math stuff, but also wonderful cartoons and stories.

Reading the sentence "The mathematician believed that every rule probably has exceptions" at age 7 basically cemented who I am