I have an interesting variation on this theme. I generally am known by my middle name, Tyler. However, on occasion, mainly when conducting official business with the government or a school, I have to reveal my first name. My first name is Stephen, which when combined with my middle name, is Stephen Tyler. Which, of course, is a spelling variation on Steven Tyler, the guy from Aerosmith.
Of course, when people find this out, I get the same litany of questions as ElectricSound. "Did your parents do that on purpose?", "Are they Aerosmith fans?", etc. In actuality, the truth is that my father's name is Stephen, and my mother just happened to like the name Tyler since she was a little girl.
The interesting part about this is that, since I generally don't use my first name unless necessary, many times I have friends, who have known me for quite a while, find this out for the first time. While it may be aggravating to have complete strangers do the 20 questions thing with you the first time you meet, it's infinitely more irritating to have it done by your friends.
Oh, and the reactions I get when I have to tell people that my street address is 1234 is another node entirely.