Fortensky, the eldest of seven children, was raised in working-class Stanton, California, and dropped out of Garden Grove, California's Pacifica High School in the 10th grade. He was drafted into the U.S. Army in 1972 and discharged three months later. He married Priscilla Joan Torres in 1972, divorcing in 1974 after having one daughter, Julie Fortensky. He subsequently married Karin McNeal and divorced in 1984.