For study today, I watched the three-video series The Wonderful World of Weird Wheels by Morphocular, which is a fun look at the mathematics of curves rolling on other curves. I think it would probably appeal to any readers who have a basic understanding of what a derivative is, and maybe to others as well, since there are a lot of engaging visuals.
The video series motivated me to read a bit about hyperbolic functions, which I never really encountered in my mathematical education. $\sinh$ and $\cosh$ were always just mysterious markings on certain calculators. I can’t say they are that much less mysterious now, but I do know their definitions and have some sense of their relationship to hyperbolas.