At 80, I won't retire from my family's 150-year-old grocery business anytime soon. I'll run it for as long as l can.

• Robin Blair runs his family's greengrocer business, founded in 1875.
• The octogenarian gets up at 4.30 a.m. and can work as late as 10 p.m., 6 days a week.
• He says he'll never retire from the trade, and it's given him the best life he could hope for.

This interview is based on a conversation with greengrocer Robin Blair, 80, the owner of JJ Blair & Sons in Darlington, in the North-East of England. It has been edited for length and clarity.

We have an old saying in our family: "There are two chairs that will kill you in life — the electric chair and the armchair."

Capital punishment won't apply to me, or at least I hope not! And there's no way I'll retire to put my feet up and sit in front of the TV.

It's not in my nature, or my blood. My father, Joe, worked in our greengrocery, founded in 1875, until he was in his nineties.

I'd sow seeds, plant cabbages, and look after tomatoes as a child

You could say I joined the trade when I was a few months old in 1940. We're based at an indoor market, and my mother would tuck me under the counter while she served the customers.

You were expected to help at the nursery almost as soon as you could walk. By the time I was 5, I'd be sowing seeds, planting cabbage, and looking after tomatoes.

My siblings and I — including my younger brother, Keith, my business partner until he died in 2013 — were given our own plot of land to work.

We were allowed to keep the proceeds. I used to grow vegetables with an easy return, like lettuce, because they matured quickly. There was a friendly rivalry among us kids over who made the biggest profit.

I couldn't wait to leave school at 15 and work full-time, even though it was physically demanding at times. We grew everything ourselves until we began moving toward wholesale.

We had a horse-drawn cart

You spent the morning harvesting and washing the produce. Then you'd load up the wooden cart and our trusty horse, Bobby, would pull it three-and-a-half miles to the market.

My grandfather, Jack, who established JJ Blair & Sons 150 years ago, was a proud man and wouldn't let Bobby leave without polishing his harness. Neither he nor my dad would dream of having a mechanical vehicle. Everything was horse-drawn.

Back then, the market ran from 3 p.m. to midnight. The manager would ring a bell at 9 p.m., signaling that you could start auctioning the stuff you had left over.

It was fun shouting out your wares to attract the highest bidder. There was no refrigeration in those days, and you'd take the leftovers back to the nursery to compost.

Our motto was "More flash, more cash," meaning that the better the produce appeared, the more money you made. I still live by that rule.

The apples gleam on our stand, and the bananas are at the right stage of ripeness. We grow our own soft fruits in our greenhouses, including strawberries, raspberries, and blueberries. They always look delicious.

We have had to compete with supermarket chains

I also pride myself on writing the signs that show the prices, both in pounds, ounces, and kilograms. The letters are spelled out nicely. It's a bit like doing calligraphy.

The glory days were the 1960s, 70s, and much of the 80s. The indoor and outdoor markets were bustling with nearly 200 stands. They were right in the center of town, a hub of activity.

Then the big supermarkets came along. It changed everything. They're fighting among themselves over pricing, undercutting us, and it's hard to compete. People like the ease of going to them, especially with the free parking.

Still, we have many loyal customers. Sadly, we're the only greengrocers left in the market today. Shoppers come for the fresh produce, the personal service, and the lively conversation.

A strong work ethic was instilled in me as a child, and I have no problem getting up at 4:30 a.m. daily to prepare for the market, which opens at 8 a.m.

I usually get back to the nursery around 3 p.m., where we also grow bedding plants. My working day can last until 8 or even 10 p.m. in the summer, to take advantage of the lighter nights.

I don't know whether the business will remain in the family

This trade has given me a better life than I could have hoped for. I wish Keith were still here, but I'm delighted to be running the business at 80.

It makes me sad to think what might happen after I'm gone. When I ask my daughter, Alyson, if she'll continue in the family tradition, she'll laugh and say, "Never say never."

Meanwhile, my long-suffering wife, Alwyn, keeps me happy and healthy, and I keep a positive outlook. It's my 81st birthday in May, and I plan to keep going for years after then.

Do you have a story about working a job longer than most? Please email Jane Ridley at jridley@businessinsider.com