Simply put, even though you can live your life at such a fast pace, that doesn't necessarily mean that love won't find you when you least expect it. Love "crashed into" his life without much warning, and the power of it engulfed him. Whereas everything before him was so routine and rushed, this new love of his is ambiguous and you never know what's just around the corner. It's got him so consumed that he can't walk away.
Simply put, even though you can live your life at such a fast pace, that doesn't necessarily mean that love won't find you when you least expect it. Love "crashed into" his life without much warning, and the power of it engulfed him. Whereas everything before him was so routine and rushed, this new love of his is ambiguous and you never know what's just around the corner. It's got him so consumed that he can't walk away.