It was surprising to me. It's one thing to know in theory that heating water uses a lot of power, and another to actually watch the power consumption of your house double when you flip on the kettle.
John: Hey neighbor!
Jill: Hey John. What's up with the super-hot weather these days? Good thing I installed that AC unit a few months ago.
John: Oh, you have AC? I do too, but I looked you up on Wattvision and your power consumption is way lower than mine.
Jill: Oh, that's because my unit has a variable speed motor. And it has power factor correction built into it so it draws much less current from the grid.
John: You're so cool Jill!