In a small town in Scotland, an aged shoemaker decided to pass on the story of shoes to three young people.

Under the careful guidance of the old shoemaker, the three young people are making rapid progress.

When they were skilled and ready to go, the old shoemaker told him, "remember, you can only use four nails at the sole."

The three young men nodded in ignorance and set off on their journey.

After a few months, three young people came to a big city to settle down. Since then, there are three young shoemaker in this city.

There is bound to be competition in the same industry.

But because the skills of the three young people are all equal, the days are quiet and peaceful.

After a few days, the first shoemaker felt anguish about the old shoemaker's remark.

Because every time he used four nails, he could not make the sole completely repaired, but he could not believe in his life. So he thought all day, but no matter how he thought, he thought he couldn't do it.

Finally, he could not get rid of his worries and had to go home with his hoe.

Second cobblers were also annoyed by four nails, but he found that after four nails were used to repair the bottom, the bad shoes always came to second times to repair them. As a result, those who repaired shoes had to pay twice as much money.

The second shoemaker secretly delighted that he thought he knew the true meaning of the last word of the old shoemaker.

The third shoemaker also found the secret. After suffering, he found that he could make up the shoes once more than a nail.

The third shoemaker thought about the night, and finally decided to add that nail. He thought it would save customers' time and money, and more importantly, he would feel at ease.

A few months later, people gradually discovered the difference between the two shoemaker.

So the second shoemaker's pavements became more and more cold, and more and more people went to third shoemaker to mend their shoes.

Eventually, the second shoemaker shops were closed.

As the days went on, the third shoemaker remained as conscientious as before to serve the inhabitants of the city.

As he grew older, he began to understand the meaning of the old shoemaker's advice: innovation, and no greed, otherwise it would be eliminated for society.

A few years later, the shoemaker was really old. At this time, several young men came to learn this craft. When they learned their skills, the shoemaker also told them, "remember, the sole can only be used with four nails."