An absolute masterpiece. All the knowledge one would really need to get started is Calculus. Well, to fully appreciate this book and learn from it, having some experience in ordinary differential equations and some rudimentary analysis is a huge plus. I say this because this book trades depth for accessibility, that is, in order for it to be widely comprehensive, it tends to only scratch the surface on most topics. However, with some basic experience in the previously mentioned subjects, one could understand the material at a deeper level.<br><br>The exercises are wonderful, and I encourage anyone to learn XPP to visualize many of the systems encountered. XPP a piece of software written by G. Bard Ermentrout in which you can plot bifurcation diagrams, solutions to systems, phase diagrams, etc (although ancient, there is a plethora of information and tutorial webpages on his site). You can also use Matlab (with Mathcont), but XPP is more straightforward (a bit janky) and FREE.<br><br>Whether you identify as  pure, applied, both or none, I highly recommend any curious academic to go through this book.