Transcript:

So, the Peak-End Rule is a psychological heuristic that determines how we remember an experience. So, the experience could be longer and more uncomfortable, but you will not remember it like that. If the peak of that experience was a good one and the experience ended on a good note, even though the unpleasant experience was longer, you will not remember it like that. 

This is the Peak-End; it's called a rule, but it's a heuristic. That's how most people remember it. And companies use this. Like when you go to amusement parks for example, there are these long lines usually. And people don't remember the long lines because the experience of the amusement park ride—the peak of that experience—is excellent, and the end of that experience of that ride is excellent. So, people don't remember the unpleasantly long lines. 

And you can do this also on a daily basis. If you end your day well and the peak of the experience of your day is a good one, you'll remember that day being a good one. Same for the week, same for the year. That's just how our brain works.