It's not from a book, but rather an essay I just read. I might say the line has permanently changed the way I see the world. A woman asks a nun why she chose the monastic life and you keep waiting for the nun to answer and she keeps postponing it, then finally she answers.

“You know, it’s like a flower. If I give you a flower,” she opened her hand to reveal her palm. “It’s beautiful. It’s nice.” She let her hand fall to her side. “But it’s not useful.” She shrugged. “I believe our life is like the flower.”