It's a story about a man who has a childhood friend that doesn't age. The man visits his friend, and discovers that his friend's childhood has continued in a sort of alternate universe. His friend listens to new episodes of canceled radio programs from back in the 50's or so (or maybe television programs, I'm not sure). His friend's mother feels a great deal of anxiety about the situation. One day, the man takes his friend outside to see the world, but this causes his friend to suffer a severe headache (or something). Shortly after, his friend passes on.
The main themes are childhood, nostalgia, stuff like that. It's a bit of a riff off Peter Pan.
I believe I only read the summary of this story, and that it's a short story (but it could be something else, like from television). Maybe I read about it on Wikipedia but they removed the page.