One summer's day, a merry Grasshopper was dancing, singing and playing his violin with all his heart. He saw an Ant passing by working hard to store food for the winter. “Come and sing with me instead of working so hard,” said the Grasshopper “Let’s have fun together.” “I must store food for the winter,” said the Ant,“ and I advise you to do the same.” “Don’t worry about winter, it’s still very far away,” said the Grasshopper, laughing at him. But the Ant wouldn’t listen and continued to work. When winter came, the starving Grasshopper went to the Ant’s house and humbly begged for something to eat. “If you had listened to my advice in the summer you would not now be in need,” said the Ant. “I’m afraid you will have to go without supper,” and he closed the door.
What is the theme?

What could be a theme of the following: 
In 1946, Robinson joined the Brooklyn Dodgers.  He became the first African American to play basball in Major Leagues.  Robinson's first game was opening day of the 1947 season. He faced the Boston Braves.  He also faced a hostile crowd.