Acharya Chanakya was still in the search of a boy who is well suited for becoming the Emperor of the Akhand Bharat while Dhana Nanda was still ruling Magadha. One day he sees a small group of children playing king and subject a boy named Chandragupta was the king and the others were his subjects. The subjects one by one came up with a problem and Chandragupta with his intelligence used to give the solutions which were fair and true. He decided to test the boy. He went to the boy and asked him to give him something as he was brahmin.
I am a extremely poor brahmin, I came here ask you something.
I want to do a puja for that I need milk, ghee, curd and cow dung. Oh king, will you give me these things for my puja?
How do you find your way to the court of King Chandragupta, Brahmin?
Sure, there are some cows over there. Whichever you like you can take.
I can neither give the amount of the cow and nor any tax. Still you will give me the cow?
No crops means no business. No business means no money and no money means that no one will give tax.
And if there won't be any kingdom then how am I a King. So I am actually helping myself and the kingdom, not you.
If you are not able to please the god, then there will be no rain. And no rain means no crops.
And if no tax means there won't be money to give the army. And a kingdom without any army will be gifted to the enemies.
At those words Acharya Chanakya was stunned. He now knew who would be the future emperor of the Akhand Bharat. He trained Chandragupta to what we know now. The Great Samrat Chandragupta.