Our set of 20 most valuable insights and models comes to an end, appropriately with a lesson about the importance of finishing well and finishing memorably.

So what better way to illustrate that than with bowel examinations?

In Thinking, Fast and Slow, Daniel Kahnemann talks about the difference between what he terms the ‘experiencing self’ and the ‘remembering self’. We can only ever experience any given event once, but we can remember it many times. Of course, we won’t remember it perfectly, so what actually happens is that we remember the most emotionally intense part of it, and the way it finishes. The rest of it we typically forget. He was able to prove this dramatically by demonstrating that people that had undergone long colonoscopies that finished comfortably, had a better memory of the experience than people who had had shorter colonoscopies which finished uncomfortably. Objectively, the people who had the shorter colonoscopies had less overall discomfort, but the memory of how it finished dominated perceptions.

This phenomenon has come to be known as the peak end rule and has many applications in the world of business and marketing. Retailers the world over train staff to ensure that customers leave the shop happy, because final impressions count. And TV advertisers are learning that to maximise attribution and effectiveness, it’s vital that branding is heightened at the moment of the greatest emotional spike within an ad, as well as at the end.

So, two lessons, and two eternally relevant ones at that:

  1. Emotions always dominate over reason.
  2. End well.