Once, at a school, an experiment was conducted. Each teacher gave each student in his class a balloon. Each student had to inflate the balloon, write their name on it, and then throw it into the school corridor.
The teachers mixed all the balloons and the students were given 5 minutes to find their own balloons.
Despite intense searches, no one found their balloon.
At this point, the teachers told the students to take the first balloon they found and hand it to the person who had written on it. Within 5 minutes, everyone had their own balloon.
The teachers summed up this experiment as follows: "These balloons are like happiness. We will never find it if everyone is looking for his own. But if we care about other people's happiness ... we will also find ours."