He soon realizes that the Dark Passenger had given him an unusual amount of confidence and an almost supernatural awareness of the world around him; now that it's gone, he feels vulnerable for the first time in his life. Dexter begins to develop sadness and anger, emotions that were once suppressed by the Dark Passenger.
Dexter quickly discerns that the Dark Passenger had granted him an unusual level of assurance and a heightened awareness of his environment; since its absence, he now feels vulnerable for the first time. He begins to feel sorrow and rage, feelings that were once concealed by the influence of the Dark Passenger.