Matt and Asperger's Syndrome

It isn't common knowledge at the time of writing; but Matt suffers from Asperger's Syndrome, a type of ASD. This has often limited his thinking, as well as his understanding of the rest of the world around him. This also granted Matt's Mentality his nickname, and (to an extent) the characterisation of Reggie. It also allows Matt to think in ways that other people do not and to interpret things differently (which can either be positive or negative, depending on how you see it).

How it inspired Reggie's personality
Reggie is, according to Matt, based on how he sees himself; annoying, stupid, interruptive, self-aware and incredibly strange. This type of self-deprication was funny to Matt, and is one of the few things that remained from before Plan B. This, he believes, is linked to his Asperger's. Had he not had Asperger's, Reggie would be massively different.