Steve had not always been Steve-O. He added the O because it made him feel big, which he needed as he had a small willie.
Also, he thought the O gave his name more of a ring to it :O get it? eh? Its funny right?
Ring? O? get it? huh? do ya? do ya? eh? right? funny? slavery? struggling to regain money lost through compulsive gambling? funny eh? eh? no? oh well.
He has many friends such as himself, his other, darker self (accessed by reciting the lyrics of any ABBA track around him) and me, ie himself.
He is well known for his willingness to whore out his body for comedic porpoises, but few know about his love of nylon. NYLON!!!!1!!!!!
- Steve, pre O-ification