On a recent walk, my ten-year-old nephew bent down to pick up a stone, which he skimmed across a river. It jumped about six times: I was impressed.

“That’s really good Ned,” I said, trying not to give away how surprised I was that he could do it.

Brought up in central London and still living there, my sister has nevertheless made sure that her son has done all the things that she did in her youth - climb trees, mess about in streams, search for crabs in rock pools, pick wild fruit and skim stones.

That’s just the tip of the iceberg - there are a million and one activities by which we amused ourselves as children.

My husband and I took pains to make sure our daughters experienced them. We took them fishing and camping, helped them to build sandcastles and fly kites.

My dad showed them how to skim stones although unlike their cousin, they didn’t master the art.

Like my sister, I made a conscious effort to keep them away from computers and get them outside for fresh air, exercise and fun that didn’t involve a menu and mouse.

I’m not a perfect parent by any means - my 16-year-old daughter would say I was the worst mother in the world - but I believe my children have benefited from this snapshot of how children used to spend their days.

I say snapshot because that’s what it is. It’s not really like my own upbringing. For a start all these activities were supervised.

My children were 11 before I allowed them to go places by themselves, yet from the age of about seven I was walking a mile to school, and racing over fields with my friends, exploring distant villages.

Between 1970 and 2010 the area in which British children were permitted to play unsupervised shrank by 90 per cent, research revealed.

We knew how to make dens and find frogspawn.

We could identify wild flowers and we knew which berries were edible. And we could make daisy chains.

Today, the majority of children have no experience of these pursuits.

Two-thirds of them children have never made a daisy chain or squelched through mud, a separate survey found. Many have also never played in woodland, climbed trees or planted seed.

Nowadays, I imagine, kids only ever get filthy in mud as a right of passage on their family’s annual glamping trip to Glastonbury.

It’s not all the fault of computers - much of it is our own paranoia about safety.

Today’s children are missing out on so much.

Yet even parents like my sister and me, who allow their offspring to dip their toes into the water of how it used to be, will never truly experience that outdoor freedom and fun we had.