In this paper, the authors focus their attention on the way magnetic circuits and permanent magnets are usually treated in most textbooks and electrical engineering courses. This paper demonstrates how this important topic is too often presented simplistically. This simplistic treatment does not allow the students to develop a complete understanding of the problem, and it leads to a misinterpretation of the sometimes wrong results obtained by using the most common formulas. A guideline and a set of examples, which could help the students to a better understanding of the topic, are presented here. (Contains 1 table and 16 figures.)