Why a spinning motor is also, quietly, a generator — and why that fact is exactly what limits its running current and lets it brake by feeding power backward.
A motor and a generator are, at the electromagnetic level, the same machine doing the same thing: a conductor moving through a magnetic field has a voltage induced in it. A generator is built to be spun on purpose so that induced voltage becomes useful output. A motor isn't built for that reason — but the moment its rotor starts turning, the exact same induction happens whether anyone intended it or not. That accidental-on-purpose generator action inside every running motor has a name — counter-EMF — and it quietly governs almost everything about how motor current behaves, from why starting current is so brutally high to why a motor being forced to overspeed can shove current backward into its own supply.