>>1709147The movie was about the effect distance has on relationships, and how it brings people apart. He longed for those days when they were young, but he couldn't just call her anymore because he didn't even really know her anymore, she was just a memory at that point. He wanted to move on, but he was worried that she hadn't moved on. At the end of the movie when she doesn't wait for him, he realizes that she's moved on and he then finds closure. Rather than chasing after a long lost memory, he smiles and walks away. It's not supposed to be a particularly tragic or sad ending, but I guess that's how most people interpret it.
