“A professor gave a balloon to every student, who had to inflate it, write their name on it and throw it in the hallway. After the professor mixed all the balloons up, the students were given 5 minutes to find their own balloon. Despite a hectic search, no one found their balloon.
At that point, the professor told the students to pick up a balloon and hand it to the person whose name was written on it. Within 5 minutes, everyone had their own balloon.
The professor said to the students: "These balloons are like happiness. We will never find it if everyone is just looking for their own. But if we care about other people's happiness, we'll find ours too."- Unknown