His father brings a list of resolves that Gatsby had as a kid. It was in a copy of the book entitled Hopalong Cassidy. Gatsby's goals were all good, and nothing that demonstrated his eventual "success". He wanted to quit smoking and chewing, read a lot, bathe often, and be good to his parents. He also devoted 2 hours a day to needed inventions.
Putting these things together, I think one could assume that Gatsby was a good ole' American boy looking for a way to make it big... legitimately.
Jay Gatsby was idolized for his success in his father's eyes, but in years of late, he didn't really know his dad at all.