To what is nick referring when he says, "Then it had not been merely the stars to which he [Gatsby] had aspired on that June night"?

I think that Gatsby emerges, at least for Nick, as a romantic idealist instead of just a filthy rich East Egger with a dubious past. Gatsby not only evokes mystery for Nick but pathos as well, 

Gatsby believed in the green light, orgastic future that year by year recedes before us. It eluded us then, but that's no matter...