Jimmy Kimmel tells jokes for a living. He has a popular late-night television show called “Jimmy Kimmel Live.” He is known for his jokes, silly interviews and a friendly rivalry with actor Matt Damon. Kimmel was also the host of this year’s Academy Awards show, or Oscars. Kimmel usually begins his late-night show by joking about celebrities, current events and politics. But on Monday night, Kimmel started his show with a story about his newborn son, Billy. Kimmel had not been on TV since his son was born last month. He wanted to tell the audience why. Billy was born with a serious heart problem. The problem prevented his blood from receiving enough oxygen. The baby needed a medical operation to repair a part of his heart. He spent many days in the hospital. But eventually, he came home. Kimmel explained that his son will need another operation on his heart when he gets older. But for now, he is OK.