This book is so good it only took me over a year to read.
Actually, though, given that it's an extremely dense textbook on a subject that only partially overlaps with my field of study, the fact I bothered to finish it speaks to it being interesting... or me being either OCD or stubborn or both. Pick your favourite explanation.
There is a lot to be found out in it, anyway, about things you've wondered about, or never wondered about and kick yourself for not wondering about after you've found out. Like what the hell kidneys do, and why fatty foods are the best thing for hangovers. Seriously.. physiology courses should be a compulsory part of all college degrees, and not just a cramming exercise for pre-meds, because the stuff that's going on in your body is really bloody impressive, not to mention handy in a practical sense (hangover cures. Seriously. Physiologists have the best ones).