The song is about a relationship coming to an end, as the singer reflects on the expectations and difficulties he had in the relationship.
The singer expresses regret over possible mistakes he may have made, while also emphasizing that a part of her will always remain in him.
The lines 'Bye-bye-bye' are interpreted as a farewell and letting go, as the singer tries to accept the end of the relationship and process it through music.
The song reflects the complexity of relationships, loss, and the hope that both sides find their own way to deal with the separation.