I'm going to get comparative here...
Not that this song directly relates to The Man on Top of the World, but in essence, this song embodies what Holly was for Johnny, and what Johnny was for Holly.
Yes, their relationship is all too brief. But that's because that was life, their life, where their time together and their happiness was short and fleeting. The two had no choice. This was their only sanctuary and foundation from the real world where they could only be free as an illusion, not as themselves. Away from the spotlight, away from the fame, away from judgement, and free from any homophobia, biphobia, or transphobia that would be alive and well if they weren't Johnny and Holly.
Holly is utopia itself, Jonathan's utopia, and Jonathan is her Amazing Grace.
Together, they didn't rock the world's foundation, only theirs.
They proclaimed love, that was their salvation.
Aside from this song's title, for me, this song represents what their relationship was about.
I'd love to know, Man on Top of the World readers:
What song represents Johnny and Holly to you? :)