It is shown that, in addition to its obvious merits in demonstrating and confirming theoretically tractable properties of electronic circuits and circuit models of physical systems, the SPICE simulation program can lead to unforeseen aspects of circuit behavior. Two specific examples are taken to illustrate this feature. In the first, it is shown how SPICE correctly predicted instability in a nonlinear capacitor model due to a physically incorrect choice of a parameter, later confirmed by a closer investigation of the theory. In the second, RF pulse experiments in an ensemble of nonlinear resonator circuits are shown to indicate temporal splitting of normal nonlinear echoes into multiple humps, which was not anticipated under approximate theory.