The prisoner slowly starts to get used to the light. First, he starts seeing shadows easily, then the stars and the moon.
Finally, the former prisoner begins to see the actual sun, and as he studies it, begins to understand even more about it.
He starts to understand how the sun created all the things he now sees, including the shadows in the cave, and he recalls his old cave buddies. He laughs at the thought of them thinking they named those shadows themselves. He now knows they got the short end of the stick.
Oh, my poor old cave buddies. I feel so bad for them.
Look at the meep!
He decides to go back down to the cave to hang out with his old friends. But, as soon as he starts playing the game with them his eyes become useless in the utter darkness. The other prisoners think he came back down a fool, since he can't play the games anymore.
Wha...? I can't see anything.
What's wrong with you?
He contemplates freeing the prisoners, but he knows that would not work. They would either turn him down since they were thoroughly enjoying life, or the men would kill him for trying to free them. He had to choose between going back out by himself, or staying in the cave with his cave buddies.
Like the Allegory of the Cave, our world, with all the things we see, is like the prison, and the fire is our sun. Going up out of the cave and understanding the things outside is like your soul making it to the world of thoughts, ideas, arguments, and real knowledge, or so Socrates says.