Roosevelt’s active and clever mind helped him greatly through periods of his illness. As soon as he could sit up, he worked on his stamp collection, began to write a history of the United States and a book about John Paul Jones—a navy hero. He was also ready to try anything that might help him to get well. A member of his family tells the following: Roosevelt got a great deal of physical exercise later simply by crawling around on the floor. Although now over forty, he spent hours crawling around his library floor like a child. Then he decided to learn how to go up the stairs by himself. Day after day he would pull himself up the stairs by the power of his hands and arms. He insisted that his family and friends watch him and talk with him, to give the impression that what he was doing an everyday routine ( 例行的 ) action.