Kronberg was born in the Bronx, New York. He graduated at the age of 16 from Bronx High School of Science, and graduated in 1968 with a bachelor's degree from St. John's College, Santa Fe, New Mexico; he then spent a year as a junior fellow at the Center for the Study of Democratic Institutions with Robert M. Hutchins in Santa Barbara, California. In discussing his time at St. John's and the Center years later, Kronberg described himself as a "Socratic revolutionary."