However, he did express great fondness for "Horton Hears a Who!" He considered it one of his most important books, as it dealt with themes of compassion, responsibility, and the value of all life, no matter how small.
He also held "The Lorax" close to his heart, as it addressed environmentalism and the importance of protecting our planet.
Ultimately, each of his books held a special place in his heart for different reasons.