In the following spoiler, I'm posting a link to a video of a street fight. If you don't want to watch someone getting knocked out, don't click the link, please. Spoiler Notice the guy in the black shirt that's trying to talk the hothead down. He gets slapped in the face and is extremely put off by it, but is content to just stand there complaining about it. The second the aggressive dude goes down, the previously nice guy flies into a rage and tries to kick him. It's a really fast change in heart. In fiction, most characters most of the time are hyper consistent. If someone likes pizza once, they will want pizza every time it's offered. If someone doesn't back down from a fight, they will never back down from a fight. The behavior of real people is much less consistent than fictional people. So if you wanted to have a character have a rapid change in heart or behavior, how would you make it convincing. Imagine that the victim of the slap in the video isn't the POV character., and you can't monologue about his internal thoughts.