Baudolino

"At that precise moment, Master Niketas," Baudolino said, "I realised that, by saving the life of my lord, I had paid my debt. But for this very reason I was no longer free to love Beatrice. And thus I realised I loved her no more. It was like a healed wound, the sight of her aroused welcome memories but no yearning, I felt that I could remain at her side without suffering, or leave her without feeling sorrow. Perhaps I had finally become a man, and all youthful ardor was spent. I felt no displeasure, only a slight melancholy. I felt like a dove that had billed and cooed without restraint, but now the season of love was over. It was time to move, to go beyond the sea."

"You were no longer a dove, you'd become a swallow."
"Or a crane."

-- in Baudolino by Umberto Eco (2000)