We watched the 1970 movie in which Milo, the main character in the book, mentioned "fibonacci". While Serena would likely be a loyal subject of King Azaz The Unabridged at Dictionopolis, I would pledge my loyalty to the Mathemagician over at Digitopolis. Hence I felt obliged to seize the opportunity and enlighten Serena on the fascinating fibonacci sequence.
"As Pilgrim's Progress is concerned with the awakening of the sluggardly spirit, The Phantom Tollbooth is concerned with the awakening of the lazy mind." (Excerpt from The New Yorker's review of The Phantom Tollbooth, 1961)
"Blockhead: The Life of Fibonacci" by Joseph D'Agnese
"Wild Fibonacci: Natures Secret Code Revealed" by Joy N. Hulme
"Growing Patterns: Fibonacci Numbers in Nature" by Sarah C. Campbell