I had taken that "test" a long time ago, and still remain astonished at how many people apparently don't notice what is going on. (It was painfully obvious to me) I think we assume that what we notice as individuals is what everyone else notices. I think acting totally normal while dressed in public is the best way to simply not draw too much attention. A great film with this theme is Le Samuri, it helps to change how we think about the chaos of being noticed, and especially remembered later on!