Based on his reading experiences, including the French Encyclopédie and Jules Verne novels, he developed an idealistic devotion to the cause of world justice, unbroken optimistic faith in the fast development of science and technology, which will solve all problems of humankind. He was not interested in university lectures, he managed to pass his exams with the help of a tutor. Nevertheless, he obtained his law degree and, at the age of 24, became a rampant adult. He wanted to make up for what he had missed as a teenager, throwing himself into the nightlife, with striking vehemence; he spent his time ruthlessly, playing cards, having fun in hunting, living in French spa towns, attended many international horse races and early automobile racings in various European countries. Francophone as was traditional in the family, he spent several years in Paris; he also traveled to the United Kingdom and the United States. Mihály became a passionate collector of racecars and yachts. As a gambling addict, he was known for his card battles, his lone card losses and his "dandy" lifestyle in famous casinos across Western Europe. The young tycoon begins to get serious and turn to politics and public life. In his youth, he was a wastrel, but as he grew older, he became devoted to more serious pursuits. In 1909, he became the President of the OMGE (National Agricultural Society), the main rural organization of the nobility. Initially a supporter of the existing political and social system in Hungary, Károlyi gradually became more progressive and left-wing during his career. In 1910, Károlyi was elected to Parliament as a member of the opposition Party of Independence. In January 1913, he was challenged to a duel by prime minister István Tisza, after refusing to shake Tisza's hand following a political disagreement. The 34-bout duel with cavalry sabres lasted an hour until Tisza cut Károlyi's arm and the seconds ended the duel. On August 5, when the war broke out, his ship has arrived to Le Havre, he has come back from his long trip from the United States. He was shortly arrested, as a citizen of an enemy country, despite Austria-Hungary was not at war with the French Republic yet, thus he was released from the prison. Later, he was arrested again for several weeks in Bordeaux for being a citizen of an enemy country. After Károlyi promised that he won't fight against the French during the war, the French authorities allowed him to return to Hungary via Switzerland.