Maybe, he had fallen in love with her long ago, when she was unwilling to lose, when she punched him, when she refused his coming-of-age birthday party, when she said, we'll never cross paths again...
It's just that at that time, he didn't understand what love was, even less so, that the reason he kept this girl by his side was not because he disliked her, but because he cared so much about her and couldn't bear to see her disappear from his world.
So he was always at odds with her, always hovering in front of her.
Seeing her with Cheng Ziyang, he always felt an inexplicable anger stuck in his chest; when he heard she was going to marry Cheng Ziyang, he worried all night and even couldn't help but call her in the middle of the night.
He always prided himself on being smart, yet he never understood his own heart, so dull for such a long time that now he realizes his feelings, he's already missed the best opportunity.
It's just like that lyric.
