Just over three years ago I knocked a child over in my car. He was about 12 and the first I saw of him was when he bounced off my bonnet and into the path of the oncoming traffic.

It was a wet November day. I was on my way to collect my elder two children from school and was uncharacteristically in the car because the younger two and I were just returning from a day trip. Both streams of traffic were moving slowly, probably no more than 15 miles an hour. The child had looked right, spotted a gap in the cars and darted into it without checking the other lane. I hit him before I could do anything about it. I saw him hit my windscreen and ricochet off and on to the tarmac. The Porsche coming the other way just stopped in time but his front tyres were pushing against the boy’s ribs and he was screaming out, not in pain but for fear that the car would drive over him.

For a moment I just sat there. I didn’t dare open the door for fear of what I might see. Every part of me went cold. Then I got out of the car. The boy had his eyes open. He was pale but I could see no blood. I spoke to him, asked his name and if he was in pain. By now he had stopped screaming. His answers were confused.

The driver behind me called the police and an ambulance and the boy was rushed off, sirens flashing to the nearest hospital. He was fine, a few bruises and no doubt a deeper regard for the dangers of the road. The driver behind me told the police that he had just run out and that I could have done nothing differently. The policeman was kind. He took my details and then rang later to inform me that the child was unharmed and that no action would be taken as it was an accident.

It was one of the most terrifying experiences of my life. I was completely blameless and the child was fine but the “what ifs” still haunt me. What if the traffic had been moving faster and he had been seriously hurt or worse? It would still have been his fault but how would I live with the damage that I inflicted. Then there are the scenarios that you dare not imagine. What if I had been on the phone, or turning round to shout at the children in the back? Then I would never know if I could have done something to prevent it.

Once I had all my children safely at home I started to shake and then I cried for hours. My husband told me over and over again that it wasn’t my fault and that everything was OK but of course it wasn’t. I did hit a child with my car. My culpability counted for nothing. I was driving. I did it.

Now, all these years on, I am still haunted by my experience. If I see anything similar on TV I will burst into tears spontaneously. It is a reaction that I am totally unable to control. I wonder if that will ever go away. I also fret that my children, who must have seen everything from their elevated positions in their car seats, can remember. I daren’t ask them for fear of raking something up but they must have recollection at some level.

A while ago I went to collect my child from her friend’s house. I misremembered the number of the house and knocked at the wrong door. After a few moments, the boy that I hit opened the door. Of course, he doesn’t know who I am but the shock for me was huge. He smiled as I explained that I had the wrong house and left but I was shaken to my core.

I think about what I did almost every time that I get behind the wheel which is perhaps no bad thing. Does the boy ever think about it? How about his mother?