This happens in Chapter 8. Gatsby and Nick have a long talk about Gatsby's past. Gatsby confides that initially he just wanted a bit of action with Daisy but fell in love. From then on he never felt worthy of her because of her high social status. This sickens Nick because he hates these vacuous ultra-rich people. He thinks Gatsby is worth more than all of them together (hence the quote). Nick laments that Gatsby is pining away for the shallow Daisy when he could be making more money and throwing lavish parties. Nick loved the old Gatsby from the beginning of the novel. He liked the mysterious paradoxical counter-culture that Gatsby represented. He does not like the more human Gatsby showing his frailties and desires. That's my take on it anyway!