His family moved from Brooklyn's Flatbush neighborhood to the working class community of Levittown, Long Island, "a mile and a half from a potato farm".

Magnus was sent to a Conservative Hebrew school three days a week and celebrated his bar mitzvah at the Hicksville Jewish Center on Long Island.

[1] He majored in modern European and Russian history at the University of Virginia, graduating in 1969 with a Bachelor of Arts degree and a commission as a second lieutenant in the Marine Corps.

In October 1974, Magnus left the Marine Corps for 15 months to work on Wall Street.

According to Magnus, "I realized three things: I really liked flying, I really liked leading people – especially Marines, and that Wall Street wasn't for me."