I recommend going through the page as it says: take the quiz seriously, try to come up with the answers on your own, and then continue on to the answers. The point of the exercise is to demonstrate a basic principle of UI design that is very often overlooked, and he makes a bunch of good cases for why it should be paid attention to. (Personally, I got a few of the answers right off the top of my head, but didn't suss the common thread until it was pointed out.)
Some longtime engineers will undoubtedly look at this and decide that it is pointlessly persnickety -- that the recommendations violate How Things Are Done, and are more trouble than they're worth. But part of what separates a truly great UI from a merely functional one is re-examining your assumptions frequently, and paying attention to those persnickety details. (One reason why our new check fraud product is going to win in the marketplace is that we *are* spending the time to design and build an unconventional but kickass UI...)