Searching for short story title

[kragg]

It's about a man who is on a spaceship but thinks he is still on earth. He talks to a psychologist about his delusions and I think it ended with the man jumping out of the ship.

 

[Metryq]

That's pretty thin stuff to go on. I doubt the following is what you seek, but it sounds vaguely like "Universe" and "Common Sense," two Heinlein novellas that were later sold as the novel Orphans of the Sky.

An immense "generation ship" suffers a mutiny, and the farmer types living on the lower levels forget they are living inside a starship. Until one day a curious young man dares to visit the forbidden upper levels and learns about the stars.

 

[otistdog]

It's about a man who is on a spaceship but thinks he is still on earth. He talks to a psychologist about his delusions and I think it ended with the man jumping out of the ship.

My guess would be "Yellow Pill" by Rog Phillips.

 

[kragg]

Rock on! I think this is it! Thanks a bunch, otistdog!