Remember: Plato was born in 427 BC.

Imagine the following scenario: A group of people have lived in a deep cave since birth, never seeing any daylight at all. These people are bound in such a way that they cannot look to either side or behind them, but only straight ahead.

Behind them is a fire. Behind the fire is a partial wall. On top of the wall are various statues, which are manipulated by another group of people just out of sight.

Because of the fire, the statues cast shadows on the wall that the prisoners are facing. The prisoners watch the stories that these shadows play out; but because this is all they ever see, they believe these shadows are the most real things in the world.

Now imagine one of these prisoners is freed from his bonds and is able to turn and look directly at the fire and at the statues themselves.

After the initial shock and disbelief, he eventually realizes that these things are real and the shadows have been false.

from https://www.sparknotes.com/philosophy/republic/themes/

There is more, but this is where all of these extremely distraught people are right now. Plato's Cave is a dead-on representation of people who only get their news from TV and the Internet instead of going out into the world and seeing things for themselves.

Some will never leave the cave. They simply cannot accept the fact that the shadows were never real. They will stay in that cave forever, no matter what we try to show them.