David Mayo spent 25 years in the Church of Scientology, making him one of the most experienced people to have served in that organisation; most do not stay longer than 3 years. His long experience as auditor to the most senior Scientologists, including L. Ron Hubbard and his wife, gave him considerable status. Following factional infighting in the early 1980s, he was subjected to physical maltreatment and psychological humiliation till he was forced to leave, then he was expelled in 1983 and was subsequently denigrated as a "Squirrel" par excellence. He nonetheless remained loyal to Hubbard's tenets and started an "Advanced Ability Center", using Hubbardian techniques and derivatives thereof. The AAC now appears to be defunct.