Umberto Eco says at the “History of Beauty“:
The thirsty person who, having found a spring, rushes to drink, does not contemplate its Beauty. He or she may do so afterward, once the thirst has been slaked. This explains why the sense of Beauty differs from desire. We can consider human beings to be most beautiful, even though we may not desire them sexually, or if we know that they can never be ours. But if we desire a human being (who might also be ugly) and yet cannot have the kind of relationship we desire with him or her, then we suffer.
James Blunt says, at “You ‘re beautiful“:
You’re beautiful. You’re beautiful.
You’re beautiful, it’s true.
I saw your face in a crowded place,
And I don’t know what to do,
‘Cause I’ll never be with you.