The subject is unrequited love or "you can't always get what you want", a story told by everyone. Included is a short epologue to the poem from Shelley's "Queen Mab", 1813.
I tell thee that those living things,
To whom the fragile blade of grass,
That springeth in the morn
Heeds not the shriek of penury; he smiles
At the deep curses which the destitute
Mutter in secret, and a sullen joy
Pervades his bloodless heart when thousands groan
But for those morsels which his watonness
Wastes in unjoyous revelry, to save
All that they love from famine; when he hears
The tale of horror, to some ready-made face
Of hypocritical assent he turns,
Smothering the glow of shame, that, spite of him
Flushes his bloated cheek.