Forster was born in 1878 in Stadtamhof near Regensburg. His father was a brewer and he had two sisters. In 1915 he had a vision in which the Sun Virgin appeared to him. The following year, Forster ended up at the medical institution of the Prüll Charterhouse in Regensburg where, to his luck, a new generation of hopeful psychiatrists of the soon to be founded Weimar Republic had begun their work.
Over the years Forster developed a complex philosophy at the hospital. He expressed this in texts and images and readily also explained it to the doctors. At the core of this philosophy was the idea of self-sufficiency and complete autonomy, which was expressed in Forster’s attempt to feed only on the secretions of his own body. Eating his own semen and faeces, drinking his own urine, he thought that, as in alchemy, they would reach an ever-increasing degree of purification through constant recycling. Forster also invented devices mounted on his head to hold on to his nasal fluids, believing that this would make him “a noble human” with a high chime-like voice, skilful in all arts and so lightweight that he could float above the ground. He also used his secretions in paintings.
Forster was not released from the hospital until 1941 as a result of pressure from his sister.