It just conveys a simple theory and if you keep it in the back of your mind, you won't be easily defeated when learning anything new.
20 years ago - Meditations : Marcus Aurelius
30 years ago - Zen Flesh Zen Bones : Paul Reps
Any time: Anything by: Robert Sapolsky, John Gottman, Early Jonathan Lethem novels, Peter Clines, Margaret Atwood
I really think this book should be read every day for at least 10 minutes.
It just blew my mind out of the park