He left college disillusioned with the art world and worked in London advertising studios before setting up a graphic design company in 1971 on the South Coast in Sussex.

"[2] In 1965 Tyrrell, whilst still a student, had met the writer, Idries Shah, who had begun introducing ideas from the Sufi tradition into the Western world.

In 1969 Tyrrell was invited to attend regular gatherings of writers, poets, actors, businessmen, diplomats, academics, craftsmen and others at Shah's home in Kent.

[5] In 1993, encouraged by the psychiatrist and writer Robin Skynner, author Doris Lessing, psychologist Joe Griffin and Idries Shah, he launched a journal, The Therapist, in an attempt to increase the scientific rigour of the field.

The journal gave Tyrrell the opportunity of publishing interviews with people whose ideas interested him, such as Richard Bentall, Doris Lessing, Robin Skynner, Margaret Heffernan, John Cacioppo, and many others.