Gatsby's essential nature is established immediately in the novel when Nick recalls that Gatsby possessed "some heightened sensitivity to the promises of life." Nick describes Gatsby's view--that life is full of promise--as a gift:
. . . an extraordinary gift for hope, a romantic readiness such as I have never found in any other person and which it is not likely I shall ever find again.
Nick recognizes that Gatsby is a romantic, a man who looks at life in terms of romantic possibilities rather than reality; his view of love is equally as romantic.
When Gatsby ran away from home at the age of seventeen, he did not seek love. He chased instead a dream of wealth, beauty, and enchantment. During his time with Dan Cody, he had physical relationships with many women, but he was never emotionally engaged. It was only when Gatsby, as an impoverished young lieutenant, met Daisy in Louisville during World War I that he fell in love. She was the first "nice girl" he had known.
For Gatsby, love becomes synonymous with Daisy. With her wealth and beauty, living in a house more beautiful than any he had ever visited, Daisy becomes the physical embodiment of all Gatsby's romantic dreams of "the promises of life":
. . . Gatsby was overwhelmingly aware of the youth and mystery that wealth imprisons and preserves, of the freshness of many clothes and of Daisy, gleaming like silver, safe and proud above the hot struggles of the poor.
For Gatsby, love is not defined or experienced in terms of reality; it is a romantic dream and experienced within the context of that dream.
He knew that he had found himself in Daisy's house "by a colossal accident," because his real identity--James Gatz born on a poor North Dakota farm--excludes him from membership in Daisy's exalted world, but dreams trump reality for Gatsby. He pursues his romance with Daisy, and when it ends, he still pursues it, trying for five years to work his way back to her and then to bring her back into his life.
Gatsby continues to experience love as his life had existed for a few brief weeks in Louisville, sitting in Daisy's gorgeous house with her in his arms, living for a little while in the world as he had always dreamed it:
On the last afternoon before he went abroad he sat with Daisy in his arms for a long, silent time. It was a cold fall day with fire in the room and her cheeks flushed. Now and then she moved and he changed his arm a little and once he kissed her dark shining hair.
When Nick tells Gatsby that he cannot repeat the past, Gatsby is both shocked by the idea and disbelieving:
"Can't repeat the past?" he cried incredulously, "Why of course you can!"
For Gatsby, love means going back to the time and the place where he first experienced the promises he had always known were waiting for him in life, even though those promises were never rooted in reality.