“Start him! I made him.”
A bit more confirmation that “Jay Gatsby” is not a real person, but instead is a creation of someone else. Furthermore, it is as if the “Jay Gatsby” that was James Gatz’s “platonic conception of himself” was not actually his own making, but instead was corrupted by his insatiable desire for Daisy, which corrupted his vision of himself.
To help improve the meaning of these lyrics, visit “The Great Gatsby (Chapter IX)” by F. Scott Fitzgerald and leave a comment on the lyrics box