In "Winter Dreams," ambition is a central theme that drives the protagonist, Dexter Green. His aspirations are symbolized by the "winter dreams," which represent his desires for wealth, status, and love. These dreams reflect the American Dream, highlighting the fleeting nature of youth and the disillusionment that often accompanies the pursuit of materialistic goals. Dexter's ambitions are never fully realized, remaining dormant like the winter season, and ultimately lead to disappointment.

Dexter's ambition is evident from his early years as a caddy at the Sherry Island Golf Club. Unlike other caddies who work out of necessity, Dexter is motivated by a desire for "pocket-money" and the freedom to pursue his dreams. His decision to quit caddying for Judy Jones, a wealthy girl, reflects his unwillingness to remain in a position of subservience, driven by his "winter dreams" of becoming wealthy and prestigious.

Dexter's goals extend beyond financial success; he seeks to remake himself in the image of the glamorous social "insiders" he admired as a boy. He distances himself from his lower-middle-class roots, even lying about his hometown to appear more socially acceptable. His ambition is not just about wealth but also about gaining acceptance and respect from the elite.

The Sherry Island Golf Club symbolizes Dexter's ambitions and the lifestyle he covets. It represents the world of the rich and privileged, a world Dexter longs to join. Despite achieving material success and gaining access to this exclusive circle, Dexter's personal life remains unfulfilled. The golf links serve as a reminder that while Dexter's dreams may have brought him material wealth, they did not bring him true happiness or fulfillment.

October filled him with hope which November raised to a sort of ecstatic triumph, and in this mood the fleeting brilliant impressions of the summer at Sherry Island were ready grist to his mill. He became a golf champion and defeated Mr. T. A. Hedrick in a marvellous match played a hundred times over the fairways of his imagination, a match each detail of which he changed about untiringly--sometimes he won with almost laughable ease, sometimes he came up magnificently from behind. Again, stepping from a Pierce-Arrow automobile, like Mr. Mortimer Jones, he strolled frigidly into the lounge of the Sherry Island Golf Club-- or perhaps, surrounded by an admiring crowd, he gave an exhibition of fancy diving from the spring-board of the club raft. . . . Among those who watched him in open-mouthed wonder was Mr. Mortimer Jones

Dexter's ambition is ultimately a double-edged sword. While it propels him to success, it also leads to his downfall. His infatuation with Judy Jones and the glamorous lifestyle she represents blinds him to the emptiness of his achievements. In the end, Dexter's "winter dreams" remain unfulfilled, leaving him with only the "solid realities" of life.