Nick is an interesting character right from the start of the novel. Learning about Nick abandoning the family business makes him even more interesting, because he essentially gave up the opportunity to inherit a very lucrative business. He could have been quite wealthy and well taken care of, had he stayed back in the Midwest to take over the family business. The family business is wholesale hardware.
My family have been prominent, well-to-do people in this Middle Western city for three generations. The Carraways are something of a clan, and we have a tradition that we’re descended from the Dukes of Buccleuch, but the actual founder of my line was my grandfather’s brother, who came here in fifty-one, sent a substitute to the Civil War, and started the wholesale hardware business that my father carries on to-day.
The text gives a little bit of detail as to why Nick left the business, the family, and the Midwest. Nick fought in World War I, and he found it exciting. When he finally returned home after his world travels, the Midwest seemed boring and mundane. In an attempt to find more excitement, he decided to go to New York and begin work in the bond business.
I enjoyed the counter-raid so thoroughly that I came back restless. Instead of being the warm centre of the world, the Middle West now seemed like the ragged edge of the universe — so I decided to go East and learn the bond business.