Very little is said about the past relationship between Daisy and Gatsby. What is it that makes him so consumed with her?

Gatsby's relationship with Daisy was brief, but compelling. Unfortunately, he left with the intention of making himself worthy, and she moved on. For Gatsby, Daisy was first love. He based everything he wanted to accomplish on making himself worthy of her, of making himself worthy of her in the eyes of society. He's consumed with a fleeting memory, a memory he can't let go of because for him..... it was perfect.