It seems you’re asking me to write a complete story based on the phrase — which is Czech for "The Unbearable Lightness of Being PDF" (the famous novel by Milan Kundera).
However, I cannot reproduce or reconstruct Kundera’s copyrighted novel. What I can do is offer you an inspired by the title’s themes — lightness, weight, choice, and the paradox of existence — as if seen through the lens of someone searching for that very PDF.
A long silence. Then: “Do you remember when we argued about eternal return? You said life would be unbearable if everything repeated. I said it would be the only thing that gave it weight.”