"I should have known"

Some replays are about a decision, where the photocopier was a moment of clumsiness. You sold the flat in 2016 and watched the street double in price. You turned down the job with the small company that everyone has now heard of. You stayed three years too long with someone, or left someone you now think you should have kept. You didn't push your father to see a doctor in March.

These replays have their own refrain, which is "I should have known". The signs were there. Anyone could have seen where prices were going. He'd been tired for months. How could you have been so blind?

The answer is that you weren't blind. You're looking back from a place where the ending is known, and that changes what the past looks like. Psychologists have studied this for fifty years under the name hindsight bias. Neal Roese and Kathleen Vohs, reviewing the research, describe it as the belief that an event was more predictable than it really was, once you know it happened. They break it into parts. One is memory distortion. People misremember what they thought at the time, in the direction of what turned out to be true. Another is a sense of inevitability, the feeling that it had to go that way. The third is a belief about yourself, that you could have foreseen it.

They also describe how it comes about. Once you know the outcome, you recall the facts that fit it and lose sight of the ones that didn't. The story of how it happened becomes easy to tell, and that ease gets mistaken for how likely it was beforehand. One consequence they name is a fixed attention on a single explanation of the past, to the neglect of other reasonable ones.

Apply that to the flat. In 2016 you had some facts. Prices had been flat for two years. You needed the money for a move. An agent told you it was a fair offer, and a newspaper you respected said the market had peaked. You also had some facts pointing the other way, and they're the only ones you remember now. Your replays go straight to the friend who said "I'd hold on if I were you", and they never stop at the newspaper. The you of 2016 weighed a mixed picture and made a reasonable call. The you of today marks that call against an answer sheet nobody had in 2016.

It's like failing a student for not knowing something that was discovered after the exam.

An objection. "But some people did know. My friend held on to her flat." Some people guessed the other way and were right. Others guessed the other way on a different occasion and were wrong, and you don't hear about it because nobody replays a disaster they avoided by luck. That your friend was right is evidence that the outcome was possible. It doesn't show that it was knowable. If it had been knowable, the price in 2016 would already have reflected it.

A second objection is stronger. "Sometimes I really did ignore what I knew. I had a bad feeling about him from the start." Then that's a real lesson, and it takes one sentence to state, as in chapter 3. "When I have a bad feeling early on, I'll take it seriously enough to slow down." That's worth having. But be careful even here. You've had bad feelings about plenty of things that turned out fine, and you don't remember those, because nothing happened to fix them in your mind. Hindsight picks out the one bad feeling that was followed by trouble and presents it as a warning you wilfully ignored.

There's a question that undoes a good deal of this, and it becomes part of the method in chapter 12. What did I know then? I don't mean what was true, or what you know now. I mean what you had in your hands on the day, including the facts that pointed the wrong way. Write it down as if you were making the case for your earlier self. You'll usually find that the decision was a fair one on the evidence, made by someone doing their best with a mixed picture, and that it turned out badly. "I made a reasonable decision and it went badly" is a sadder sentence than "I was a fool", in a way, because it means the world is less controllable than you'd like. But it's the true one, and it doesn't need going over four hundred times.