Please enjoy my rooster boy and one of my hens relaxing in the sun with me: I picked up an ancient differential equations textbook to fill in the big gaps in my diffeq knowledge. (Turns out making plans to get married with only tenuous approval from your parents is not really conducive to studying...) It's nice -- the writing is concise and the author answers a lot of questions that I had the first time through. Also, the typesetting is beautiful and the book smells nice. Planning out my semester and realizing just how much work I have to do. Fortunately almost all the deadlines are self-set, so hopefully that'll be better for my brain than external deadlines that come too quickly.
It's "Elements of Ordinary Differential Equations" by Golomb and Shanks. Published by McGraw-Hill in 1950! I picked it up out of a pile of free textbooks, so I can't swear to it's superiority over other texts. The first couple chapters have been as enjoyable as a diffeq book can be, though!