I guess since a punch wouldn't fundamentally change the individual i'll pick a personal target; a selfish, manipulative, backstabbing son of a ***** I once trusted and believed was a friend, he betrayed me and manipulated and hurt someone I care about very much.
He probably doesn't know it because he's such a thoughtless, selfish and abhorrent little twat but he is the reason I don't have much trust in people anymore and the reason I try to keep certain aspects of my life separate.
Anyway, yeah, he'd be punched very hard.
Sorry about that little outburst, nice to get things out sometimes.