How was Dan Cody involved in shaping Gatsby into the man he became?

Dan Cody was a millionaire that Gatsby met when Cody's yacht dropped anchor in Lake Superior.  For young Gatsby, "that yacht represented all the beauty and glamour in the world."  When Cody realized how ambitious and quick Gatsby was, he began to employ the young man "in a vague personal capacity," and he served as "steward, mate, skipper, secretary, and even jailor" when Cody drank too much.  Thus, "It was indirectly due to Cody that...

Dan Cody was a millionaire that Gatsby met when Cody's yacht dropped anchor in Lake Superior.  For young Gatsby, "that yacht represented all the beauty and glamour in the world."  When Cody realized how ambitious and quick Gatsby was, he began to employ the young man "in a vague personal capacity," and he served as "steward, mate, skipper, secretary, and even jailor" when Cody drank too much.  Thus, "It was indirectly due to Cody that Gatsby drank so little."  

In other words, it was from Cody that Gatsby learned how to be rich: how to act, what to do, what to buy, how to speak, and so on.  Even his way of calling almost strangers "old sport" seems like the expression of a much older man, likely picked up from Cody.  Cody also seems to have taught Gatsby the importance of self-control, and this is why Gatsby serves copious amounts of alcohol at parties but never partakes himself.