All this is from the Nick and Gatsby’s car ride in Chapter IV:
He reached in his pocket, and a piece of metal, slung on a ribbon, fell into my palm
“Here’s another thing I always carry. A souvenir of Oxford days. It was taken in Trinity Quad – the man on my left is now the Earl of Doncaster.”
Taking a white card from his wallet, he waved it before the man’s eye’s . . . “I was able to do the commissioner a favor once, and he sends me a Christmas card once every year.
Gatsby’s pockets are both literally and figuratively deep.