His friends, who were of many social classes, nicknamed him "furious" for the way he played during games. Though his parents forced him to quit the sport, he secretly joined another league without his parents knowledge. .
He was defiant and daring as a boy. He would do all sorts of crazy things. He once walked a pipeline over an enormous gorge. He also had a childhood gang that would cause problems in their town. .
Ernesto's parents left the house open to all the neighbors no matter how poor or how rich. His mother, Celia de la Serna y Llosa was a rebellious woman who embraced feminism as early as the end of the first world war. She dared to cut her hair short and even crossed her legs in public. His father was a humble, open-minded man. Both the parents had arguments a lot. .
Ernesto entered medical school in 1947 when he was 19. He went to study more about allergies and his illness, asthma, then later on he studied leprosy. At this time Ernesto took no part in revolutionary student movements at Buenos Aries University. .
In 1949 he made the first of his long journeys, exploring northern Argentina on his bike and for the first time coming into contact with the very poor, lepers, and remnants of Indian tribes. After he went back to take tests, Ernesto went on another journey, this time much longer and accompanied by a friend. He explored much of southern Argentina, Chile, Columbia (where he was arrested but soon released)Venezuela, and Miami. All of this was traveled by motorcycle and hitchhiking. He worked casual jobs for money. .
After his 7 month journey he went back to Argentina and finished medical school at the age of 25. He became a doctor knowing he did not want to become a middle-class general practitioner. .
Ernesto then went to Bolivia during the National Revolution, then Guatemala during the socialist Arbenz presidency where he refused to join the communist party, even though he was by now a Marxist, which meant losing a chance of government medical appointment.
