Five monkeys are in a room wearing shock collars. A banana is placed in the middle of the room. If any of the monkeys try to get the banana, all five are shocked. So, the monkeys immediately go for the banana and all of them get shocked. They don’t know why, but they know it hurts. After enough failed attempts, they are eventually able to associate those attempts with pain. Several weeks in, the monkeys know not to try to get the banana, and it goes bad.

One day, a monkey is taken out of the room and replaced with a new monkey that isn’t wearing a shock collar and is unaware of the Banana Shock law. As this new monkey walks towards the fresh banana, the four other monkeys are shocked. The next time the new monkey tries to eat it, the others immediately intervene and beat the ever-living shit out of it to prevent themselves from being shocked. After enough beatings, the new monkey knows that if it goes to get the banana, it will get the shit kicked out it. The banana goes bad.

This process is repeated, each new monkey being beaten by four others, three because they don’t want to be shocked and the fourth because it thinks that’s what you do to those monkeys that go for the banana. The fourth monkey may also be thinking that since they were beaten after trying to eat the banana, it’s only fair that this new monkey receive the same treatment. After a few weeks, the monkeys doing the beating know you can’t go to the banana, but only half know why. Then, only one knows the whole story.

You now have five monkeys and zero shock collars.
No one goes near the banana.
No one knows why.