This textbook uses an innovative, fresh and rigorous approach to the analysis of analog circuits. The author guides students to leverage the psycho-cognitive concept of basic pattern as an efficient calculation tool, going beyond its traditional use for the qualitative visual inspection. In this journey, the reader is not left alone to face statements such as “it is easy to prove that” or “it has been proven elsewhere that”. All formulas and theorems are proven step-by-step. In particular, the proofs of the theorems on frequency response and stability have been made as intuitive as possible. The author thus demystifies and makes available to the student these relevant theorems, which are usually scattered over decades of reading and/or in several textbooks and papers. Two chapters focus on exercises of increasing difficulty, most of them discussed fully and solved step-by-step, allowing students to strengthen and test their knowledge. Moreover, the first two chapters introduce the history of microelectronics and physics of fundamental electron devices.