I don't chase the perfect shave. Normally I do either 2 passes and some touch up, or, if the shave is going good, I will do 3. I'm just looking for the best I can do, today. I try to pay attention to how my face feels. The moment I feel irritation(usually along the neck under the jaw line), that's the last pass I'll do. Time to stop.
Each shave is different. Each is fun. It's more about the trip than the destination, at least for me.