Why does the Punisher narrate? He’s keeping his War Journal is all.
The Punisher comics have been around for a while, and like many comic book character the Punisher has his share of odd times, weird habits, and personal idiosyncrasies. Firstly he kills people, not many heroes do so willing as the Punisher does.
Besides being a ruthless out of the norm hero, the Punisher also has a shopper’s list of problems. An identity crisis, psychopathic tendencies, murderer, ruthless, unable to feel pain ( mostly) so talking to himself is the least of his problems. If anything the War Journal, his narration and/or log of events is a way of staying alive. In that keeping an active record of his work, recording his war.
He’s ensuring the war is fought, that the campaign is moving forward, that there is some reason within the madness. By serving as his own narrator, he is documenting his one man struggle against the criminal world and the world at large.
Who better to tell us about the character than the character himself? The internal machinations of his mind are what keep his body moving forward. In the Punisher’s devastating life, the greatest weapon he has is his mind. His mind is the most powerful weapon he has in his war, he isn’t a mindless killer he’s fully aware of himself and his actions; which makes him all the more intimidating.