Because you don't own any Hawaiian shirts, but don't want to bear the stigma of being a "less-than-colorful character" when there's an Aloha Friday at work. . .

Because you're hoping that the information has finally gotten into the collective subconscious from the countless times that people have been told, and you'll no longer have to come up with clever variations on the standard responses to, "Ohh, and what's worn beneath the kilt?"