Three nuns are flying in a rocket ship towards Mars. They look out the windshield and see a giant red planet.
One nun looks out the window and says, "This planet is beautiful."
The other nun says, "This planet is terrible."
The third nun replies, "I think it's all about perspective."
The fourth nun says, "I think this joke is about jokes and perspective."
The fifth nun replies, "I think all of this is a joke, and I think that all of you are just figments of my imagination."