Logic Riddles

Question: In 2000, a 40-year-old doctor told his son that, when he was a little boy, he decided to be a doctor after seeing on the internet a heart transplant being performed on a puppy with a defective heart so that the puppy could live a normal life. The boy then thought about being a doctor too someday so that he could help people in a similar way. What's wrong in this story?

Question: What did the banana say to the elephant?

Question: I am life without death, death without life, a world with no space, space with no world What am I?

Question: A child asked his grandfather: "When you were young, what were you?" The grandfather replied, "I am one hundred, nothing, one thousand, one and one hundred". What's his career?

Question: Something you know nobody knows, and everyone knows something you don't. We all know something, nobody knows everything, and you know something someone doesn't know. What else could nobody know?