Or like, to put it in terms that the "read what you like, who cares if you exclusively read kids' stuff" crowd are at a reading level to understand:
In the book "Green Eggs and Ham," the main character insists that he will only eat things he likes, and refuses under all circumstances when presented with an opportunity to try something new. At the end of the novel [spoiler alert] he agrees to Sam-I-Am's request and tries them, and he realizes that he was depriving himself of a favorite food for years, just out of fear of disliking something he ate. He learns a lesson, moving forward, that if he tries new things outside his comfort zone, that he may dislike some of them, but will enjoy many of them, and if he doesn't try new things outside his comfort zone, he will not like anything but the one thing he already eats.
Can you think of any situations in your own life where Sam-I-Am's teachings might be applicable?