This person never knew the advantages to having an uncommon last name. (Mine's an Americanized spelling of a French spelling of a Basque name):
Telemarketer: Hello is mister *confused pause* (something not even close to my last name) available?
Me: Nope. *click*
The only notable problem -- there's only 8 of us left in the US with this last name, so I can't deny all those embarassing things on the internet, or even blame my twin brother, like I can for things in person.
(there are a few alternate spellings in the Ellis Island records, but as best I can tell, there aren't any left in the US)