The long answer: Back in high school, I got involved in musical theatre, pastly in an attempt to break out of my shell. One of the casts I was in had a Jon (me) and a John. To keep us separate, the rest of the cast and crew started calling us by our characters' names - mine was 'Milton'.
By the time college had rolled around, I had decided to re-invent myself. I wanted to be more out-going and more social. And at freshman orientation, I met 11 other 'Johns', so I started introducing myself as 'Milton'.
Over time, as friendships have gotten tighter and stronger, and as I've grown more comfortable with myself, I've come to rely on Milton less and less. He's still there, and I still use him - being around large groups of people or being "on stage" takes a lot of energy out of me. But more often, he's supporting me and working with me instead of acting in my stead. For now, it looks like he'll be part of me forever.