The Hindsight Fallacy
Hindsight is 20/20...[1] Gosh, I sure don't like that idiom. When uttered, that stupid phrase assumes far too much. It does not account for opinions, past experiences, or unreliable narrators.
The Hindsight Fallacy is a trap that many fall into because it causes people to base their predictions about the future on an inaccurate understanding of the past.
Eyesight
When you have good eyesite, it is often described as 20/20 vision:
“A person with 20/20 vision can see what an average individual can see on an eye chart when they are standing 20 feet away,” - Dr. McKinney, ophthalmologist[2] 
See?[3] 20/20 vision isn't perfect. It is what an average person sees from 20 feet. But when people tell you "hindsight is 20/20" they just blurt it out as if everybody has perfect, unsullied memory of an event. Then, because somebody uttered that phrase, everybody just nods and agrees.
Memory
Memory is not like a video recorder; it is malleable and can be changed by what we hear, see, or think about after an event occurs. The problem with false memories is that they are often just as vivid and convincing as genuine memories, making them difficult to distinguish from the truth.
Our false memories are constructed by overemphasizing those bits of information that confirm our beliefs and forgetting or downplaying information that contradicts them.[4]
My Evidence
At a jobsite, a worker approaches me and states that he has rolled a backhoe over because the ground was wet. The embankment he was driving the tractor on gave way and because things were so slippery, the machine tumbled over the side.
"I knew that grass was wet, but I drove over it anyways. Hindsight is 20/20," he said.
After figuring out that nobody was hurt except for a $40,000 tractor, I told the guy "You had 20/20 foresight, when you knew the ground was slippery, why didn't you use that?"
He stared at me dumbly.
This is why I don't like the phrase "hindsight is 20/20." People use it far too often as if to explain the dumb shit they do.
References
- ↑ Gee, I knew it all along!
- ↑ https://www.aao.org/eye-health/tips-prevention/what-does-20-20-vision-mean#:~:text=%E2%80%9CA%20person%20with%2020%2F20,Northwest%2C%20Oregon%20City%2C%20Ore.
- ↑ Pun intended
- ↑ Confirmation bias.
