this is probably the best math textbook I've read so far. most concepts explained fairly clearly, but not with an excessive level of rigor. unlike nearly other academic reference author, Strang isn't afraid to let his personality shine through. he tells the reader about his favorite equations and makes endearing little remarks under the example problems: "This solution makes me realize that the initial value y(0) is like having a delta function at time t = 0. The solution 'jumps' to y(0). I don't know if you agree with that." for a subject that can be so depressing, I like that he's having fun.
the most valuable thing that Differential Equations and Linear Algebra taught me was what kind of mentality to approach a differential equation with. Strang consistently reminds the reader to predict the form of the solution before attempting it, and even though I don't remember all of the formulas now, this backwards-solving method has always stuck with me.
4/5 because there were some notation issues and problems with the answer key that gave me massive headaches. occasionally, parts of the equation are condensed or omitted without warning, and other times, terms appear from seemingly nowhere. I'll admit that in several instances I threw this book against my wall and cried. but that's just the name of the game, so no deduction there.