Foster was born in 1980 in London, England. He studied Astrophysics at Cambridge University. At this time he was overwhelmed by feelings of despair and loneliness, which eventually led to physical illness and a personal breakdown soon after graduation. He was convinced he was going to die. Foster returned to live with his parents, reading and studying for a year on spirituality, searching for relief from his depression. This ended in 2006 with the dissolution of the sense of separation, which he understood to be a spiritual awakening:
As the story goes, I was walking through the rain on a cold Autumn evening in Oxford. The sky was getting dark; I was wrapped up warm in my new coat. And suddenly and without warning, the search for something more apparently fell away, and with it all separation and loneliness.
And with the death of separation, I was everything that arose: I was the darkening sky, I was the middle aged man walking his golden retriever, I was the little old lady hobbling along in her waterproofs [...] I was the raindrops falling on my head (although it was not my head, I did not own it, but it was undeniably there, and so to call it "my head" is as good as anything). (https://en.wikipedia.org/wiki/Jeff_Foster_(spiritual_teacher))