I took some time to finally read Paul J. Nahin's very enjoyable book,
An Imaginary Tale, on the history of complex numbers and analysis. He did a surprisingly good job of making even the longer worked out calculus examples an enjoyable romp. Good brain food, but not for those unfamiliar with calculus, and even then probably best for those already familiar with most of what's in the book but who are interested in its history and connections they may not have appreciated as a student. I learned a thing or two, and even made some appropriate updates to my
History of Hypercomplex Numbers timeline.