After receiving his doctorate at age 25, he became an assistant professor at the University of California, Berkeley, but resigned abruptly two years later.
In conjunction, he issued a social critique opposing industrialization and advancing a nature-centered form of anarchism.
He became associated with a group of likeminded boys interested in science and mathematics, known as the "briefcase boys" for their penchant for carrying briefcases.
Throughout high school, Kaczynski was ahead of his classmates academically.
At the University of Michigan, Kaczynski specialized in complex analysis, specifically geometric function theory. Most of its theories were proven in the 1960s, when Kaczynski worked in it." According to mathematician Donald Rung, "[Kaczynski] probably would have gone on to some other area if he were to stay in mathematics." After resigning from Berkeley, Kaczynski moved to his parents' home in Lombard, Illinois, then two years later to a remote cabin he had built outside Lincoln, Montana, where he could live a simple life with very little money and without electricity or running water, His original goal was to become self-sufficient so that he could live autonomously.
He taught himself survival skills such as tracking game, edible plant identification, organic farming, bow drilling and other primitive technologies.