The lyrics suggest that the protagonist is reminiscing about a significant love from the past and the memories shared together. They reminisce about the way they felt, the moments they had, and how special their connection was.
Lines such as "I could see forever with you at my side" and "I never knew a love so complete" illustrate the depth of the protagonist's feelings and their longing for what they had.
The chorus, which repeats the phrase "We belonged together," emphasizes the strength of the bond and the sense of loss that the protagonist feels now that it is no more.
Overall, the song speaks to the bittersweetness of love and loss and the universal human experience of longing for what is no longer within reach.