The traditional treatment of the electric circuit in textbooks can be criticized in at least three respects: A) Knowledge of the global aspects of the electric circuit as a system is essential for a deeper understanding. However, this is not sufficiently emphasized. B) The presentation of the term "potential difference" or "voltage" as energy per charge is too abstract, without reference to surface charges that are always present. C) The treatment of the electric circuit, based on Ohm´s law and Kirchhoff´s rules, is exclusively based on stationary states, without including the ever-existing transition processes. This article concentrates on the global aspects of the electric circuit as a system and its importance for a deeper understanding; it also provides detailed information for corresponding classroom activities. The other two critical points are treated in subsequent articles.