Why did Helenhave any fits of temper while she was with her parents on the trip to see the eye doctor?

In the summer of 1886, Helen's parents took her to a famous eye doctor in Baltimore. She enjoyed everything about the trip – the train, the new people and the change of routine. "During the whole trip," she writes, "I did not have one fit of temper; there were so many things to keep my mind and fingers busy."