For a normal person, being held at gunpoint would cause layers upon layers of panic in the brain which would then result in them either freezing up or panicking uncontrollably. Needless to say, being held at gunpoint is a traumatic experience that practically messes with the mind.
Not for Hajime.
In that instant, his mind then unlocked another memory that he had repressed for so long— his personal classes with his father. It's not that he repressed it because it was an abhorring bad memory, but because it was one of the few good memories he had with his father whenever he was home and not out there on a business trip.
Every Sunday, when his father was still alive, Hajime would always find himself experiencing a new event in his life— be it foraging in the woods somewhere, shooting wildlife, or just applying to a language school. His father never failed to surprise him back then. Up to his death, everything came as a surprise.