- 1954 (17 years old)
By 1954 at age 17, Bobby began experimenting with harder drugs, mainly heroin, which caused him to develop an addiction to the substance. That summer, he appeared in the stage play Ah! Wilderness at the Pasadena Playhouse. In September, Bobby returned to Hollywood Professional School for his last year of high school at his request.
- 1955 (18 years old)
Bobby graduated from Hollywood Professional School in 1955.
- 1956 (19 years old)
Sometime in 1956, at 19, Bobby joined the Beat Generation, a subculture of Beatniks who took part in drug use and promiscuous sex, which is promoted by their art. Bobby was introduced to Wallace Berman (an influence of the avant-garde/beatnik culture) by best friends: Dean Stockwell and Russ Tamblyn (former child actors).
In the summer of 1956, when Bobby was 19 years old, he was arrested on a marijuana charge. As the summer progressed, Bobby and a friend, Lester Furgason, were arrested for bean shooting at two women from a car.
On December 3, 1956, Bobby eloped with his girlfriend, Marilyn Verna Rush (whom he met at a party in Manhattan Beach), after around 5-6 months of dating, in Mexico to avoid their parents’ objections. This marriage was later annulled (not legally recognized).