Nothing beats natural light at its best, especially in CA, but gee, all sorts of people default into shitty depressing natural light situations (MA, I'm looking at you) that could be trounced by a mediocre artificial setup. If you listen to the tone of the rhetoric here you'd think Munger was killing babies, when in fact the light situation evidently doesn't even reach everybody's threshold for the simple action of buying a decent lamp. Shrug.