When did thirty get to be so old? | Nick Carraway: Idiot.

I was thirty. Before me stretched the portentous, menacing road of a new decade.   It was seven o’clock when we got into the coupe with him and started for Long Island. Tom talked incessantly, exulting and laughing, but his voice was as remote from Jordan and me as the foreign clamor on the sidewalk or the tumult of the elevated overhead. Human sympathy has its limits, and we were content to let all their tragic arguments fade with the city lights behind. Thirty—the promise of a decade of loneliness, a thinning list of single men to know, a thinning brief-case of enthusiasm, thinning hair. But there was Jordan beside me, who, unlike Daisy, was too wise ever to carry well-forgotten dreams from age to age. As we passed over the dark bridge her wan face fell lazily against my coat’s shoulder and the formidable stroke of thirty died away with the reassuring pressure of her hand.   So we drove on toward death through the cooling twilight.

Nick Carraway here contemplates his recent realization that today was his birthday and that he is now thirty years of age. In it we see the romanticism he felt towards Gatsby's lifestyle and the lifestyle of East Egg fade away, in part due to the blow-up between Tom and Gatsby, but also in part due to the weight he feels at having his twenties behind him.

Nick here was become a dark mirror for Gatsby. Whereas Gatsby is always reaching hopefully for the past, Nick now looks ahead to the future as something "portentous" and "menacing." He has become different from the rest of them, no longer adults desperately seeking to go back to being children, but a man who looks ahead and does not necessarily like what he sees of his future if he continues down this past. He speaks as though he wishes to change it, something that again places him at contrast with Gatsby, with Gatsby always trying to reinvent his past while Nick now seems determined to reinvent his future.   

Nick's viewpoint of Tom Buchanan has changed as well, commenting on how he "talked incessantly," but then goes on to say that both his voice --and the city behind them (meaning East Egg) now seemed remote. Nick is moving past his need to have Tom as a friend. He's grown tired of him and will soon become disgusted with him. In comparing his to "the city lights behind" Fitzgerald illustrates that it is more than just Tom that Nick has become disillusioned with, but everything Tom represents: East Egg, New York, and the dream of an Old Money fortune. It is the entire lifestyle that Nick has become disenchanted with, not just Tom or Daisy or their affair.

"Thirty—the promise of a decade of loneliness, a thinning list of single men to know, a thinning brief-case of enthusiasm, thinning hair." The repetition of the word "thinning" here shows how Nick feels about the prospect of turning thirty. "Thinning" here represents bad feelings -- exhaustion, tiredness, and fatigue. "A thinning list of single men to know" alludes to anxiety regarding marriage and growing up, the desire to stay in his fun, single twenties.

Were it not written before the stock market crash and the "dirty thirties," I would also say that the foreboding way in which Nick speaks about the portentous thirties. As it is, these elements seem to simply be incredible foresight on the part of Fitzgerald, but may be narrative coincidence. The "menacing road of a new decade" seems to suggest this, with the new decade not only being Nick's thirties but also the Thirty's in general.

He speaks highly of Jordon for perhaps the first time in the novel without another comment to undercut it. In comparing her to Daisy he flightiness now does not seem like a bad thing, it now seems like a choice to not get hung up on the events of the past as Daisy had. To not " carry well-forgotten dreams from age to age."

Most interesting though is the final statement: "So we drove on toward death through the cooling twilight." This statement can be seen two ways: both literally, and as foreshadowing. Literally, driving towards death can be seen as just continuing with life. In a way we are all driving towards death, in that no matter how we live our lives it is where we are all heading towards. "Driving" instead of simply "heading" implies a certain degree of intent though, as thought we are, despite ourselves, almost trying to get there. It speaks to the destructive nature of the American upper class and of the boozing lifestyle Nick has been a part of for the last few months, driving himself towards death. As foreshadowing however, this statement prophesises the all-too-soon death of Myrtle Wilson in just a few pages, hit by Daisy and Gatsby in their car.

Tonally, the entire passage reads like a sombre regret on the part of Nick. Regret at the way he'd lived his life up to this point, regret at what was to come, and perhaps even (from the future vantage point through which he spins this narrative) regret for what happened, or didn't happen, with Jordon Baker. It is, as he says, the end of one age and the coming of the new. And although he has grown weary of the drama in East Egg in general and of the  Buchanan's in specific, he is not totally honest in his forward-looking speech. Much as Gatsby looked back on times past with Daisy, Nick looks back on times past with Gatsby, of the fun they'd had; parties and women and romantic drama.

It is best summed up by another line, said by Nick, a few pages later: "I’m thirty,” I said. “I’m five years too old to lie to myself and call it honor." It is my favorite line from the novel, and could I have written 1000 words on that alone I would have. Though the line itself doesn't have enough meaning, I realized, it is a response to the passage above. It speaks to the immaturity of the Buchanan's, and even to Gatsby himself -- all of them over thirty, all of them lying to themselves and calling it honor. This line, though drenched in bitterness, acts as contrast to the passage above. Despite his acrimony, Nick will be a better man in his thirties than those he'd chosen to accompany himself with in his twenties.