A teacher brought some balloons to his school and gave him…

A teacher brought balloons to his school and gave one to each pupil. He then instructed them to write their names on their balloons, leave them on the floor and leave the classroom.
Once outside, he told them: “You have five minutes for each of you to find the balloon with your name on it.” The pupils went back in and searched, but the five minutes were up and nobody had managed to find theirs.
The teacher then said to them: “Take any balloon and give it to the person whose name is written on it.”
In just a couple of minutes, all the pupils had their own balloon in their hands.
Finally, the teacher said:
“Children, balloons are like happiness. Nobody is going to find it by looking for their own alone. On the other hand, if everyone looks out for each other’s, they’ll quickly find the one that belongs to them.”