Plenty - 'Never Be Mine'

The song is by Kate Bush, focusing on Susan's longing.
https://www.youtube.com/watch?v=iwI9C2xHReo

"It's that whole thing of how, in some situations, it's the dream you want, not the real thing. It was pursuing a conscious realization that a person is really enjoying the fantasy and aware it won't become reality. So often you think it's the end you want, but this is actually looking at the process that will never get you there. Bit of a heart-game you play with yourself."