I HAVE to use a pen name! I mean, anyone who picked up a book written by Katniss Roger Atreides would wonder what freaky weird imagination said person would have. (Atreides isn't my real last name, I stole that from Dune, but the Katniss Roger part is.) So, I use one out of three pseudonyms when I write. Gretchen Eaglehart for short stories, Annalise D'Eath for dramatic novels, Chloe Montana-Cruz for comedy books, and my real name for screenplays. Plenty of famous authors have used fake names. Right off the top of my head- George Sand, Geoffrey Crayon (who is Washington Irving), Diedrich Knickerbokker (who is also Washinton Irving) It's just easier not to be yourself.