Salute to Dr. Seuss

Some quotes of his:

• "You have brains in your head. You have feet in your shoes. You can steer yourself, any direction you choose."
• "Today you are you, that is truer than true. There is no one alive who is youer than you."
  
• "Today is your day! Your mountain is waiting. So... get on your way." 
  
• "And will you succeed? Yes indeed, yes indeed! Ninety-eight and three-quarters percent guaranteed."
  
• "Sometimes the questions are complicated and the answers are simple." 
  
• "If you never did, you should. These things are fun, and fun is good."

I have always loved Dr. Seuss. His books were full of wisdom and just plain fun to read. What is your favorite Dr. Seuss book and why is it your favorite?