Carnegie asserts that we are most vulnerable to anxiety during leisure time. He argues that keeping busy is an antidote to worry, as the human brain can only focus on one thing at a time.

The author describes how one of his students lost interest in life and became a nervous wreck after two of his children died within months of each other. One day, the man reluctantly agreed to build a toy boat with his four-year-old son. Absorbed in the task for several hours, he forgot to feel anxious. From then on, he kept anxiety at bay by undertaking jobs around the house.

Another of Carnegie’s students, Tremper Longman, was the treasurer of a fruit company. Longman’s worries about the changing conditions of the market led to insomnia. However, by working 16-hour days, he cured his sleeplessness and had no time for introspection. Longman maintained this routine for three months, and his anxiety disappeared.

The author provides examples of famous people who kept busy to overcome grief and preserve their sanity. Poet Henry W. Longfellow was traumatized and grief-stricken after witnessing his wife’s death in a fire. He recovered by focusing on the positive activities of parenting his children and translating Dante.