People make their own world. To cultivate concentration they must think and do only one thing at a time. Concentration is the art of continuous and intense application to a task. It is not an abstraction; therefore it cannot be offered as an excuse for carelessness. Here¿s an example: A young man who worked in a bank was assigned to collect a note for $75,000. He received the customer's check for the amount, had it certified, and returned to the bank. Upon arriving at the bank, he immediately engaged a fellow worker in conversation, and then was sent out again for another errand. He loitered on the way, and when he returned, the bank had closed and everyone had gone home. That night the young man told his father how he came to have the check still in his pocket.