You’re asking me to define an abstract concept that no one has managed to explain since time began. You sort of sprang it on me,” Gansey said. “Why do we breathe air? Because we love air? Because we don’t want to suffocate. Why do we eat? Because we don’t want to starve. How do I know I love her? Because I can sleep after I talk to her. Why?
Maggie Stiefvater, The Raven King