A nice story!
Once a great scholar in the days of old went to a library in Baghdad to borrow some books. He found two scholars eagerly going through all the books in the library and writing some of the words, which were written in those pages. Puzzled at their actions, he came up to them to find out if he could help them in some way.
He asked them: My friends, what is it that you hope to gain from going through all these books? They replied: We are writing down words of wisdom, of the ancient scholars in order to be successful in all the endeavors we undertake in our lives. He said to them: There are three things? If you have them, you will not succeed.
The men were immediately interested and asked him excitedly: What are they? And he said:
Worry of yesterday, sorrow of today, and fear of tomorrow.
If you overcome these three things, you will always emerge successful in all your endeavors throughout your life.