Context: Popper left school at the age of 16 and attended lectures in mathematics, physics, philosophy, psychology and the history of music as a guest student at the University of Vienna. In 1919, Popper became attracted by Marxism and subsequently joined the Association of Socialist School Students. He also became a member of the Social Democratic Workers' Party of Austria, which was at that time a party that fully adopted the Marxist ideology. After the street battle in the Hörlgasse on 15 June 1919, when police shot eight of his unarmed party comrades, he became disillusioned by what he saw to be the "pseudo-scientific" historical materialism of Marx, abandoned the ideology, and remained a supporter of social liberalism throughout his life.

Question: At which age did Popper first attend university?
Answer: 16

Question: What political doctrine interested Popper in 1919?
Answer: Marxism

Question: Which Austrian political party did Popper join as a youth?
Answer: Social Democratic Workers' Party of Austria

Question: What incident killed several of Poppers Marxist political comrades?
Answer: street battle in the Hörlgasse

Question: To which political philosophy did Popper continue to adhere after moving away from Marxism?
Answer: social liberalism

Question: What age did Popper enter school?
Answer: Unanswerable

Question: When did Popper become disillusioned by social liberalism?
Answer: Unanswerable

Question: What subject did Popper never attend a lecture on?
Answer: Unanswerable

Question: What party rejected Marxist ideology at the time?
Answer: Unanswerable

Question: How many police were shot in the street battle of Horlgasse?
Answer: Unanswerable