Made to Stick

I was reading "Made to Stick", explaining what makes an event, an story linger in your audience's mind for a couple of hours, months or even years. Just got to the chapter about the "surprising" factor. The author explains that emotion is supposed to help us to survive. For example, when being angry, our brians literally stop thinking process so we can focus on the event and get out of danger quick.

Anger also enforces the belief that we are correct, do you remember last time when you were angry with someone, you cannot rationalize but only understand "I was right, it is not my fault"?

Similarly, surprise, the emotion urges us to note there is a change in our thinking pattens. We tend to be comfortable to contant events. A out-of-blue change is more likely to make us think, wanting to get to the bottom of the sudden turn. Because it is a signal to change our guessing routine, thus, the unexpected sticks to our minds longer.