She dwells with Beauty—Beauty that must die;
And Joy, whose hand is ever at his lips
Bidding adieu; and aching Pleasure nigh,
Turning to poison while the bee-mouth sips:
Ay, in the very temple of Delight 25
Veil’d Melancholy has her sovran shrine,
Though seen of none save him whose strenuous tongue
Can burst Joy’s grape against his palate fine;
His soul shall taste the sadness of her might,
And be among her cloudy trophies hung.

John Keats

There's nought in this life sweet
If man were wise to see't,
But only melancholy,
O sweetest Melancholy!

John Fletcher, Melancholy

“Melancholy is the pleasure of being sad”

It express everything...

"we must die to one life before we can enter into another!"

Anatole France

Flow, my tears, fall from your springs!
Exiled for ever, let me mourn;
Where night's black bird her sad infamy sings,
There let me live forlorn.

John Dowland, Flow my Tears