"You're a long time dead
So I'll forget that you said"
In these 2 lines the singer is trying to get over the girl
"If I can't have you
Nobody can have you
Nobody can have you"
But as the singer who was being strung along at the time is now in love with this girl, since she can't be with him, nobody else will as his heart is now infatuated only with her even after all this time.
"You're a long time dead So I'll forget that you said"
In these 2 lines the singer is trying to get over the girl
"If I can't have you Nobody can have you Nobody can have you"
But as the singer who was being strung along at the time is now in love with this girl, since she can't be with him, nobody else will as his heart is now infatuated only with her even after all this time.