“One of us is not smart enough or educated enough, having nothing but common sense. He won’t make it very far in the world without scholarship, so let’s not share our money with him. He should go back home.”
The fourth couldn’t be bothered to study from dusty dry books, but he had a great deal of common sense.
One day they got together to talk and decided that all their accomplishments and learning were pointless if they didn’t go out in the world to meet people, see places, gain a little political power, and make a little money. So they decided to travel together.