Quantum mechanics is thought to be a very difficult subject, in part because its main principles seem illogical or enigmatic. I call these principles the "mysteries" of quantum mechanics, but I show that they can be logically explained by applying only a few simple and rational assumptions. In this brief book I show how these assumptions (my "postulates") can dispel the mysteries of quantum mechanics. I do not rely on complicated mathematics, and this 53-page book (updated in 2015) is intended for the amateur scientist.