I was (like many) forced to read The Great Gatsby in high school, though I wish I hadn't as I was incapable of truly appreciating it at the time.

As others have mentioned, Fitzgerald's prose is unbelievable. In just a few words he can paint vivid imagery in your mind with layers of depth and analysis to accompany the emotions. The story and characters are beautifully written with a natural complexity that avoids the cliche 'good guys' & 'bad guys' we typically experience.

Just from my perspective alone, I found many themes and interpretations to the story which resonated with me, just to name a few:

• Clinging to the past and trying to repeat history expecting a different outcome. Recently this has tied nicely into my romantic life, where I've been noticing some repetition compulsion.
• Nick's character in general was someone I found myself heavily relating to, as I feel I tend to be the listening ear for the many people around me, which puts me in the center of some complicated situations. Many of his thoughts and reservations he keeps to himself about people around him reminds me of how I likewise internalize my judgements towards others but am able and willing to keep the peace. Even with complete strangers it's not uncommon for me to hear 'wow I'm not sure why I shared so much with you'—it's an interesting phenomenon!
• Obviously the more commonly discussed themes of Fitzgerald's criticisms of the American Dream
• Gatsby (I believe by design) is somewhat of an inspiration—at least to me. Despite being deeply flawed in core areas, I think he's overall an admirable character who is an honest victim of unfortunate circumstances.

And those are just the themes that resonated with me! There are a billion different things to take from this book, and I feel it's probably worth re-reading every few years as I'm sure there's more to get from it as we develop in life and stumble on different issues that resonate with us.

Watching the 2013 movie after finishing the book, I'm a fan.