This is true though... Microwaves work around 1000W, at which point we just have enough power to shake one of our losest (in terms of molecules) elements. It's been a while, but I too was taught that the step to heating anything else with microwaves was way too high, but only being able te heat water is enough for most food-related cases as many contain these. (You won't be able to heat up uncooked spaghetti, for example.)