In Chapter 6 of "The Great Gatsby," how long did Jay Gatsby stay in college? Why?

Although he described himself as an elite "Oxford man", Gatsby initially attended "the small Lutheran college of St. Olaf in southern Minnesota".  He worked as a janitor to pay his way through, and was quite unhappy with this situation, believing that he was meant for much better things.  He remained at the college for only two weeks (Chapter 6).