Why "Mister Marvelous"?

"Mister Marvelous", by the way, is a moniker I used a long time ago when I was writing a humorous advice column for a church newsletter.  I consider Mister Marvelous to be my prideful alter-ego, my Mr. Hyde.  To varying degrees, I manage to keep him hidden in the basement, but sometimes he fights his way up the stairs and bursts into the daylight.