Look at what Henry Gatz says to Nick in chapter 9 and even more importantly, look at what relic from Jay's past his father brings with him to New York - the book with the notations written in it. Each one of the six resolves that young Jimmy Gatz wrote in his book would probably be a point made in Henry Gatz's eulogy to his son. I think Henry would lead with something like, "If Jimmy would have lived, he'd have been someone great. He was bound to get ahead because he had a big future before him....". Henry would dwell on the positives of his son and the resolves, as well as that very disciplined schedule, show a determined, driven boy. The last resolve, "Be better to parents" would have been a fitting conclusion to the eulogy, too.