My problem with the way the topic is being presented here is not just that the mental model is too simple, but that it is so much simplified that it becomes int

My problem with the way the topic is being presented here is not just that the mental model is too simple, but that it is so much simplified that it becomes internally inconsistent. Resistance is voltage over current, here's LED, it does not have resistance. Or maybe it has more than one resistance, depending on voltage. Battery is a voltage source, wait, no it's not, it has internal resistance.