Once upon a time, there were three babies and an ogre. The ogre kept them chained inside a cave facing the wall and with their backs against the entrance of the cave so they could never see what was happening outside of the cave. They were not allowed to go outside and experience the world.
Since they grew up in the dark, their eyes adapted to the darkness and the only thing they could see were shadows on the wall in front of them coming from objects reflected by the light outside of the cave.
Since this is all they had seen all their life, shadows on a wall, life seemed normal to them; they believed that this is the way in which all people lived.
Out of boredom, they started giving names to the shadows on the wall and guessing what the shadows could be. Identifying the shadows became a fun activity for them.
One of them was the smartest, and he never missed identifying the right shapes of the shadows. The second guy was correct most of the times and the last one was almost always wrong with his guesses. Because of this, the two later guys always looked up to the first one; they thought he was super smart as he was always correct.
Many years later after the boys had grown up, the ogre went for a walk one day. At the same time, a man from the outside world was walking by and heard the three guys talking. The man walked into the cave and was stunned to see these young men chained inside the cave. Still in shock at what he had found, he asked… “What are you guys doing here? Who is keeping you here? This is so wrong… who would do such a thing to you?
As he asked, he reached into his backpack and pulled his tools to cut the chains of the smart guy who immediately screams at him… “What are you doing? Leave me here, this is my home! Why are you taking away my chains?”
The stranger kept on releasing him while saying… “No, you don’t understand. It is not normal to live life like this. You shouldn’t be here. There is a whole world out there waiting for you. You shouldn’t be here”
“Really?” -the smart guy says- “OK, I want to see this great outside world you speak of, where is it?”
Just as the stranger tries to release the other two young men, he hears the ogre so they both run away promising the other two men that they’d come back to free them as well.
Lead by the stranger and almost blinded by the sunlight, the smart guy keeps on running until they get to a safe place. It takes him quite some time to adapt his eyes to the bright light from the sun, but once he does, he is marveled at the things he is seeing. The stranger starts showing him and explaining all kinds of things like colors, flowers and objects like cars, houses, buildings, and other things we normally see in the world we live today.
All of a sudden, the smart guy understands the impact of having being chained inside that cave for so long. He realizes all what he had missed from the outside world and that there are millions of things that he wants to see and experience in this world. Then he thinks about his friends in the cave and wants to go back and free them to share and discover this outside world with them too.
He decides to go back to the cave and tell his friends about this “outside” world, but he soon discovers that they have the same reaction that he did as he tries to break the chains that keep them in the cave.
They asked him to put the chains back on them because this is their world and they perceive it as normal. He tries to convince them to no avail. Finally, one of them says… “OK, we will go with you but first tell us… What is that shadow on the wall right now?”
As the smart guy tried to focus on the wall he couldn’t see anything. He couldn’t answer because his eyes were used to the bright sunlight now and they were taking longer to adapt to the darkness of the cave.
His two friends just looked at each other in disbelief. From their perspective he had lost his intelligence. This smart friend that they always looked up to for answers had become dumb.
From their point of view, he came back dumber from the outside world so they decided not to follow him.