Sherlock/Looking For Alaska crossover.
Looking for Alaska is a book by John Green and it has almost as much creys as Sherlock.
Here’s the original quote:
“You can’t just make me different and then leave,” I said out loud to her. “Because I was fine before, Alaska. I was fine with just me and last words and school friends, and you can’t just make me different and then die.” For she had embodied the Great Perhaps—she had proved to me that it was worth it to leave behind my minor life for grander maybes, and now she was gone and with her my faith in perhaps. I could call everything the Colonel said and did “fine.” I could try to pretend that I didn’t care anymore, but it could never be true again. You can’t just make yourself matter and then die, Alaska, because now I am irretrievably different, and I’m sorry I let you go, yes, but you made the choice. You left me Perhapsless, stuck in your goddamned labyrinth. And now I don’t even know if you chose the straight and fast way out, if you left me like this on purpose. And so I never knew you, did I? I can’t remember, because I never knew.”