It's your study that gives you new skills, not the books, having said this, the following guided the most valuable learning experiences in my life: "What is Ma

It's your study that gives you new skills, not the books, having said this, the following guided the most valuable learning experiences in my life: "What is Mathematics?" by Richard Courant taught me to think at a higher level of abstraction. I read it after I realized the parts of SICP (which recommendation here I obviously second) I liked most were the math-related parts and I think it is fair to call it a SICP for mathematics, at least I don't know a book that comes closer. Then I also used Courant's "Differential and Integral Calculus" and Spivaks "Calculus" with his very detailed answer book, and this way I self-taught myself enough material to finally be able to do some reasonably serious math, e.g. proofs. After reading "Compilers: Principles, Techniques, and Tools" I wrote my own implementation of grep with state machines, then a compiler for a simple language and finally understood what a programming language really is. "Programming Language Pragmatics" was a very useful book here, too, thanks to it teaching me a range of different possible semantics for common concepts in programming languages I was able to learn new languages much more easily and easily spot bugs that I would otherwise spent hours on. "The Mindful Way through Depression" and the accompanying CD with guided meditations taught me to meditate and meditation forever changed the way I react do difficult situations. "Starting Strength" taught me correct exercise technique that completely changed the outcomes of my strength training.