Barry Mazur, who is a professor of mathematics at Harvard, also only has a PhD. He left the Bronx High School of Science in his junior year to attend MIT withou

Barry Mazur, who is a professor of mathematics at Harvard, also only has a PhD. He left the Bronx High School of Science in his junior year to attend MIT without a diploma. He then neglected to complete an ROTC requirement at MIT, but he was already accepted to Princeton's PhD program, so he never bothered to get his Bachelor's degree. A few years later, he got his PhD in mathematics at the age of 22, which remains his only degree.