Lots of things. I read about the conceptual revolution that the theory of evolution has produced in the biological sciences, the nature of evolution, phylogeny in general, the heritability and genetics of human qualities, the genetic underpinnings of society, the evolution of co-operation and social behaviour, the social universals, development of religion and mythology, and mythic universals; about origin of life; about origin of genetic controls of development, origin of different forms of reproductive behaviour, and genetic basis of behaviour; about cognitive sciences and its physical basis, the broad outlines of information processing in the human brain, and the origin of different forms of cognitive ability; about human evolution and dispersion, and similarities between humans and other primates and other animals; about ancient history and linguistics with particular focus on the ancient cultures of the middle east and India, the dispersal of the Indo-Europeans, their original homeland and their language, the origin of Dravidians and other peoples of India, and try to understand the difficult arguments concerning Nostratic and other ill-defined superfamilies of languages; about development of the various basic concepts in the sciences and mathematics; and about elementary concepts in mathematics like set theory, category theory, sheafs, large cardinals and ordinals and various concepts of infinitesimals, group theory and homotopy theory.