"In this I was seeing the things that I would later identify as crucial in helping people through major trauma. It was the pragmatic, active things that helped. When I studied counselling later, I realised I had gone with my mid brain, the primal part of myself, and strengthened myself by being active rather than passive. My practice is at the trauma end of the stress spectrum as well as normal work stress."
It was also subsequent experiences that moved him further on his path - particularly a training accident when he was a Lieutenant Commander in Naval Control of Shipping and Supply for the New Zealand Navy. In 1986 during the exercise, two smoke bombs were let off - and McEwan, having been a leader and so the last to move out, breathed in toxic smoke.
"My immune system collapsed - I had massive chest infections and was on ACC for three years."
Part of the therapy, he said, was learning coping strategies. "I wasn't expected to survive - and was given high doses of steroids. It was through help from Don Oliver Gyms in West Auckland, and general focus on recovery that got me through."
McEwan says he has always been a maverick - and that was particularly true when he was studying philosophical psychology. He was a tutor of ethics at Auckland University at the time.
"I, and a few others were rebels - we were existentialists and at the time, that was not liked. The head of department, who was dying of cancer came back to work for a day to fire me and the others - I was fired in good company".
"The plan had been to get a doctorate in philosophy - and that was now closed to me. I did social work for four or five months, and then an education diploma. I needed to return to university to finish my Masters in Philosophy and English.
"This is when I became a wharfie - I saw this as a way of working and studying. I became a member of the union and worked as a tally-clerk and waterside worker for ten years. I finished my Masters and then did a doctorate in theology - this helped me bring together all my interests and I wrote three books."
McEwan says he's not bitter that he was fired and that that changed his path as well. "I can see now that what happened gave me a better outcome. It helped me form my therapeutic approach - there is no bitterness."
He joined the Naval Volunteer Reserve. Was first an ordinary sailor, then became an officer. "I had a wonderful ten years where I could study and work. I got to see the last of the old cargo ships coming through. It was a time of transition where I was among a great group of guys.
"One thing I can say is the navy and working on the waterfront was not boring - I can't stand boring. When things went quiet on the docks, I brought out my books to study."
And then came the fateful training exercise.
Viktor Frankl, the Austrian neurologist and psychologist and also Holocaust survivor was one of his inspirations. Frankl spoke of the importance of finding meaning - and how it was often a person's attitude that showed whether they would live or die, even in the extreme environment of a concentration camp.
"I was determined that I would survive. One of the things that helped was to focus on the book I wanted to write on naval history. This was to preserve that history before the people died. And even though I was so ill and fatigued, I managed to do it."
In 1991, McEwan got into practice after been approached by a breast cancer surgeon John Harmon who said, "You know what it's like to have a piss-off-and-die diagnosis - I want you to work with breast cancer patients," McEwan says. "This was because he believed, as I did, that you could mobilise the immune system. We could do things to pump people up so they could recover faster."
He also wanted McEwan to help the husbands. "I joined him to do the counselling".
"Twenty years later, I'm still passionate about the cancer work - and still focused on Frankl's philosophy.
"At the beginning the oncologists I worked with were sceptical - it was one of them that called me Dr Stress - but they did turn around... they said they could tell between a woman who had seen me and one who had not."
McEwan says: "My approach is different from most - and mainly I learn from my patients. For estate agents it's position, position, position. In my field it's listen, listen listen... It's think, think, think."
"If you don't listen, you don't learn. I will pick things up that others have missed, simply because they haven't asked the right questions.
"I've found that when you look back at where you've come from, you say that's it. That's why I've got to do it differently from those who are more mainstream. The sausage machine approach doesn't help people. What is needed with stress and trauma is wisdom and to really hear. People need to be really heard."