“PUT your shoulders back.”

My mum used to say that to me a lot in childhood. “You’ll stay like that if you don’t stand up straight,” she would warn me.

I would shoot my shoulders back and walk away bolt upright like a soldier on parade. But it would only last until I was out of sight, then I’d go back to looking like someone who was carrying a heavy boulder uphill.

I was, what in those days adults used to term, a ‘dreadful slouch’. Teachers used to use the expression all the time too, telling us to stand up straight so as not to damage our spines.

This was among many pieces of bodily advice doled out to us kids in the sixties and seventies, all of which we took seriously.

We believed it, and carried on believing it into adulthood. I used to tell my eldest daughter that slouching would be bad for her and nag her to pull back her shoulders. Poor girl. She’s a fully fledged doctor now, so she’s more than likely aware that such words are claptrap.

Slouching isn’t, apparently, bad for us. It doesn’t harm our spines. In an academic blog, Harley Street consultant Dr Chris McCarthy explained this, his words finding their way into the national press.

“There’s a pretty good reason why slouching doesn’t damage our spines," he says, "It's because our spines are designed to allow movements as diverse as Olympic weightlifting to limbo dancing. If you’re a sloucher, rest assured that it isn’t really bad for you and is as good as any other posture you adopt.”

If only I’d known, I'd have happily slouched my way through my youth.

Us kids were misinformed.

It’s like being told not to kneel to avoid varicose veins. I remember exactly where I was when that snipped of valuable information was imparted: I was about ten, helping my dad, who was scoring at a cricket match. I was kneeling on a chair to raise myself up in the score box. The woman scoring for the other team leant over to pass on the valuable advice. From that day foreword I was careful not to kneel, and would pass her words on to friends.

We girls were also told that crossing our legs could cause varicose veins . It’s all untrue. Pressure on areas of your leg can exacerbate the symptoms of varicose veins, but it doesn’t create them. Yet advice of this sort, given when you’re growing up, sticks with you.

Even as adults, many of us are guilty of making sweeping assumptions about what causes this and what causes that. And

I used to get told that reading under my blankets - no duvets in those days - using a torch would damage my eyes. If I was ever caught doing so by my parents I’d get the usual lecture. I’d worry that my eyes would never recover, but I’d carry on doing it anyway. It hasn’t done me any harm.

I still get ticked off for reading in bed. Now it’s my husband lambasting me for scrolling through the news. “Your brain will stay active - you’ll never get to sleep,” he will say, without any reference to scientific study.

I’ve read bits and pieces backing that up - about blue light stimulating the protons or neutrons, or some such twaddle. If anything I fall asleep more quickly having spent a few minutes on my phone.

If we ever crossed our eyes as kids, we’d be told: “Don’t! You’ll stay like that.” It’s not true. Crossing your eyes is generally not harmful and will not cause lasting damage to your vision.

If only we kids had had the internet, we could have looked up all these things. But, all things considered, I'm glad we grew up without it.