"They asked the rose: 'Who made thee so lovely in form and face? I marvel why thou art thorny, why finding thee is pain!'
 It said: 'Thou findest the sweet with the bitter; whatever costs dear is better; when the lovely is cheapened it is no longer worth even dried fruit."
("The Knight in the Panther's Skin" by Shot'ha Rust'haveli - 12th century medieval epic poem).