Once upon a time, there was a boy. Well, that isn't quite sufficient. This story involves a lot more than just him.
Once upon a time, there were two boys and two girls. We'll call them First, Second, Third, and Fourth. First was a beautiful girl, tall and willowy. She had big brown eyes that drew everyone in. She was easy to love. Second was a boy (the one we first started talking about) who had a lot of ideas about who he wanted to be, but none about who he was. Third was also a boy, and he had no idea about who he wanted to be, but he knew who he was, more-or-less. Fourth was a girl, just as beautiful as First, except no one saw it. Fourth thought she was in love with Third. Third and Second both thought they loved First. First just wanted to be friends with all of them.
Eventually, each of them learned about each of the others and who they liked. First was very sad to learn that the people she thought were her friends just wanted to be her boyfriend. Fourth was very sad that Third liked First instead of her. Second was sad because it seemed like nobody liked him.
A bit later, Second realized how great Fourth was. He started to see how beautiful she was. But he felt it would be wrong to chase after her after he had chased First. He didn't want Fourth to feel like a lesser choice. He did start to see how the two of them could have been the best friends in their little group. But he missed his chance. Instead, Fourth started spending time with other people. People who were mean to Second. People who were more popular. And as time went by, she forgot about Second.
In the end, Second found happiness elsewhere. But it was too late for him to be friends with any of the people from this group. They built their lives without him, and so he did the same. So even though Second is happy, he's also a little bit sad.