This book is based on material taught in general and special theoretical physics courses given by I.B. Khriplovich at the Physics Department of Novosibirsk University, Russia. It is assumed that the reader is acquainted with fundamentals of classical mechanics, classical electrodynamics, quantum mechanics, and (in the last chapter only) relativistic quantum mechanics. These fundamentals are not discussed explicitly but instead demonstrate, by solving concrete problems, how they work in practice. Indeed, according to Newton, "in studies of science, examples are more useful than rules. To the best of Khriplovich's knowledge, most of these problems have never been discussed in textbooks, and it is believed that this is certainly true for the solutions presented. In all the text's discussions, reliance is on intuitive, qualitative arguments, the only exception in this respect being Chapter 4 which contains a consistent presentation of the semiclassical approximation in complex plane.