Question

Which line from Extremely Loud and Incredibly Close reveals a nostalgic tone?
Even after a year, I still had an extremely difficult time doing certain things, like taking showers, for some reason, and getting into elevators, obviously.
A lot of the time I’d get that feeling like I was in the middle of a huge black ocean, or in deep space, but not in the fascinating way.
It’s just that everything was incredibly far away from me. It was worst at night. I started inventing things, and then I couldn’t stop, like beavers, which I know about.
We used to Greco-Roman wrestle on the floor in there, and tell hilarious jokes, and once we hung a pendulum from the ceiling and put a circle of dominoes on the floor to prove that the earth rotated.

Answer 1

The last line: "We used to Greco-Roman wrestle on the floor in there, and tell hilarious jokes, and once we hung a pendulum from the ceiling and put a circle of dominoes on the floor to prove that the earth rotated."

Reason: the phrase "we used to" and the recounting of playful, shared past activities express longing for earlier, happier times—key markers of nostalgia.