Part of Dexters charm in the original series was his confidence and ability to pass himself off as a normal person. It makes sense that in the beginning he struggled with this and had to learn over time to adapt, but it is a different experience watching the original sin Dexter be so aloof and awkward to comical proportions. Michael C Hall Dexter was capable of being a chameleon and turning on the charisma when needed. Original Sin dexter hasnt even come close to figuring that strategy out yet.