Haruki Murakami's short story "Birthday Girl", available to read online, is about a girl working part-time as a waiter who gets to make a special wish on her twentieth birthday. In the frame story, she is telling an unnamed first-person narrator about the events of her twentieth birthday. She asks him(?) what wish he would make, if he were in the same situation as her on her twentieth birthday.
I took some time to think about that, but I couldn’t come up with a single wish.
"I can’t think of anything," I confessed. "I’m too far away now from my twentieth birthday."
"You really can’t think of anything?"
I nodded.
"Not one thing?"
"Not one thing."
She looked into my eyes again—straight in—and said, "That’s because you’ve already made your wish."
What does this mean? What is the wish he already made, and how does she know? Does it relate to the questions of what her wish was and who he is?