CONTROL YOUR THOUGHTS
Idam pure cittam acari carikam yena'icchakam yattha kamam yatha sukham
Tadajj' aham niggahessami yoniso hatthippabhinnam viya ankusaggaho.
In the past, this mind has wandered as it liked, wherever it liked, at its own pleasure.
Now I will control my mind wisely, as a mahout (holds in check) an elephant in rut. 
One day, Samanera Sanu was requested by the elder bhikkhus to recite some religious discourses. When he had finished his recitation he solemnly recited, 'May the merit gained by me for reciting these sacred discourses be shared by my mother and my father.' At that time, a spirit, who had been the mother of the young samanera in a previous existence was listening to his recitation. When the mother spirit heard his words, she felt elated and promptly cried out, 'My dear son, how happy I am to share your merit. You have done well, my son.' On account of Samanera Sanu, the mother spirit came to be very much respected and was given precedence in their assemblies by the devas and other spirits.
As Sanu grew older, he was not happy with the religious life and wanted to return to the life of a layman. He went home and told his mother in the present existence of his intention. His mother did not want him to leave the Order and tried to persuade him to give up the idea, but he was quite firm in his decision. So, the mother promised to give him his clothes after his meal. As his mother was busy cooking his meal, the spirit who had been his mother of a past existence, thought, 'I must try to stop him from leaving the Order.' So, the young samanera was possessed by her and he rolled on the floor muttering incoherently. The mother got alarmed, neighbours came and tried to appease the spirit. Then, the spirit spoke out, 'This samanera wants to leave the religious Order and return to the life of a layman. If he does so, he will not be able to gain his emancipation.' After saying these words, the spirit left the body of the samanera and he became normal again.
Finding his mother in tears and the neighbours crowding around him, he asked what had happened. His mother told him everything that had happened to him and also explained to him that to return to lay life would be very foolish. Sanu then realized his mistake, returned to the monastery, and was ordained a full member of the Holy Order.
Wishing to help Venerable Sanu to realise the ultimate goal, the Buddha exhorted him, 'My son, one who does not restrain the mind which wanders about cannot find happiness. So, control your mind as the trainer controls an elephant.' Reflecting mindfully on the admonition given, Sanu attained Arahanthood. He mastered the Tipitaka and later gained wide recognition as a great exponent of the Dhamma.