When should you put down that pen?

While I was out walking my dog at 7.45 this morning, I saw a sharp-suited young executive on his way to my local train station. He had a bulging briefcase in one hand and it was a good job he was walking on the opposite side of the road to us because he wasn't really looking where he was going.

He was rather more concerned with the conversation he was having on his mobile phone. Now, I can't prove that he wasn't on the phone to his kids; I can't prove that he wasn't discussing with his wife what they are having for dinner tonight. But I'd take a very big bet that he was on the phone to the office - well before he's even started what could be a long and very stressful commute to work.

Talking of which, I'd take an equally large bet that he's one of those people who works on the train; who absolutely must find a table on which to put their laptop and spread out all their papers (which might contain commercially-sensitive information, by the way). He probably gets into the office early, has a sandwich at his desk at 1pm (hence the bulging briefcase containing his lunch!), works late at the office and repeats the process on the way home - right down to making more work calls as he heads home.

Is that you? Am I describing someone you know - a friend, a neighbour, a work colleague? Probably. Because too many of us don't know where work starts and stops every day. We don't know when to put down the pen, switch off the laptop, turn off the phone. I was like that once - I'd write columns at all hours of the day and night, make calls late into the night; in the end, after almost three decades, it nearly killed me.

My career in journalism started in 1986; by 2006 I started getting major epileptic fits. After almost 18 months during which I didn't change my lifestyle and the fits got worse, a professor of neurology told me I had no understanding of how close I'd come to killing myself. I wasn't sleeping properly or eating properly because I was constantly thinking about work.

He put me on a cocktail of drugs with quite unpleasant side effects and made it clear I had to change my lifestyle. I did but the damage was already done. I don't have fits now, but in 2013 I suffered a stroke which my doctor said was directly related to work-stress.

I survived the stroke, but I am now medically retired at the age of 53. I give talks and write pieces like this about the dangers of work-stress, but I suffer massive bouts of fatigue and am restricted to three hours of 'brain-work' a day.

At one of my talks recently, I met an accountant who told me that after ten years of stress, he had a Eureka moment one day and was now firmly of the view that if it couldn't be done in 32 hours a week, it wasn't that important. I am starting to hear that kind of thing more often but the vast majority of us, especially self-employed people, still think like the man I saw this morning.

Are you one of them? If so, I hope these words make you pause for thought. My adherence to that lifestyle nearly killed me. Please don't let it kill you.