In high school LaVey became something of an offbeat child prodigy. Reserving his most serious studies for outside the school, he delved into music, metaphysics, and secrets of the occult. At fifteen, he became second oboist in the San Fransisco Ballet Symphony Orchestra. Bored with high school classes, LaVey dropped out in his Junior year, left home, and joined the Clyde Beatty Circus as a cage boy, watering and feeding the lions and tigers. Animal trainer Beatty noticed that LaVey was comfortable working with the big cats and made him an assistant trainer.

Possessed since childhood by a passion for the arts, for culture, LaVey was not content merely with the excitement of training jungle beasts and working with them in the ring as a fill-in for Beatty. By age ten he had taught himself to play the piano by ear. This came in handy when the circus calliope player became drunk before a performance and was unable to go on; LaVey volunteered to replace him, confident he could handle the unfamiliar organ keyboard well enough to provide the necessary background music. It turned out he knew more music and played better than the regular calliopist, so Beatty cashiered the drunk and installed LaVey at the instrument. He accompanied the "Human Cannonball", Hugo Zachinni, and the Wallendas' high-wire acts, among others.

When LaVey was eighteen he left the circus and joined a carnival. There he became assistant to a magician, learned hypnosis, and studied more about the occult. It was a curious combination. On the one side he was working in an atmosphere of life at its rawest level - of earthy music; the smell of wild animals and sawdust; acts in which a second of missed timing meant accident or death; performances that demanded youth and strength, and shed those who grew old like last year's clothes; a world of physical excitement that had magical attractions.