Matt's mother wanted to name him Christine.
Of course, when he turned out to be a boy, he was given a boy's name (his father's choice) - and before he thought to ask his parents why Mail, or why Christine, they were gone and so was his chance to find out.
Then, at the orphanage - patiently working his way through volume after volume of French literature, because that was the only alternative to the oral presentations, and he hated speaking in front of people - he discovered Gaston Leroux's Le Fantôme de l'Opéra. He loved it. He convinced Mello to read it too (the blond boy's only complaint was that Raoul was a sissy); they listened to the Andrew Lloyd Webber score over and over again (a very bemused Near discovered Matt singing "Angel of Music" to the bathroom mirror one night, turning the budding diva redder than his hair); they even snuck a "boat" and an electronic keyboard down to the basement and played Phantom's Lair (L never threw out the flower, clumsily adorned with a black shoelace-ribbon, that was tossed through his window one day, accompanied by a burst of mischievous giggling). And sometimes Matt used Chris as a false name - (Mello always smirked knowingly and introduced himself as Erik) - because, even if it wasn't entirely true, he liked to think of Christine as his namesake-of-sorts.
Even Christine flinched the first time, Matt reminds himself guiltily, shame battling revulsion as he lifts Mello's bandages and sees the left side of his face.