My first mistake was wardrobe. It had been cool and cloudy in the morning. A little bit of air made the leaves on the trees quiver nervously.

‘Hmmm, not quite shorts weather,’ I thought as I glanced out the window, the weight of the decision to be made resting uneasily on my shoulders. I went for jeans and a shirt. How was I to know what would follow?

As the day grew old it became steamy. Hot, sticky and sweaty. Not a classic sunny summer day but something greyer, more uncomfortable.

My jeans were already quite a tight fit. My waist has been expanding like boiling milk in a saucepan in recent months. I ran a marathon just over a year ago. Now just bending over gives me a similar sense of athletic achievement.

The seeping heat had seemed to make the jeans contract even further. They felt like warm custard poured onto my legs. I found it was almost impossible to bend my legs at the knee.

My shirt was moist like a sail in a yacht. My ‘It won’t let you down’ anti-perspirant had hoisted the white flag at the first sign of moisture. My sweaty, cherry red face completed the effect.

We were at the park. Again. I had been pushing the swing for what seemed like hours and my arms were damp and tired. I always get envious of other parents when I take my son to the playground. They all seem to be able to sit on the bench happily chatting to each other and enjoying the sun while their kids play.

It’s not that way with my boy. If he is going down the slide then I have to go down the slide. If he is at the top of the climbing frame then I have to be up there too. If he is playing on the pirate ship then I’m usually Red Beard and have to stomp around pretending I’ve got a wooden leg and shouting ‘Waaaar me hearties!’ while other parents look on bemused.

Now I just wanted to sit down. The place on the bench next to the mummies appeared to me like a mirage across the park. I had an idea.

I lifted my son out of the swing and asked him if he thought he could beat the world record for running around the grass strip which encircles the park. Never one to duck a challenge he was immediately excited. I told him the starting line was at the park bench. I barked ‘Ready, steady, go!’ and off he went, panting and spluttering. I sat down on the bench and stretched my legs. I was satisfied. Some of the mummies even started to make small talk with me. For just a short moment I knew what it felt like to be normal.

Some moments later my son arrived back gasping and looking at me expectantly. I glanced at my watch. ‘Bad luck son, just outside the record, you’d better have another go.’ And off he went again.

This might seem to you cruel. It was. I sat back pleased with myself.

However my masterplan was about to become my second, and much more serious mistake. After my son arrived back at the bench this time he demanded, ‘Daddy, you run with me!’

‘No, no,’ I said with growing alarm. ‘I’m too old to run.’

I could see the tears gathering in his eyes and I knew a tantrum was not far away. Some of the mummies started to shift uncomfortably.

‘Please daddy, please run with me,’ he whimpered pathetically.

The mummies were watching me. I knew I was trapped. I pulled my creaking joints and bones up from the bench and started a light jog.

‘Faster daddy, faster.’

I tried to run. It felt horrible in the tight clothes and oppressive heat. As I mentioned before I couldn’t bend my legs effectively in the jeans so the run was more like a robotic straight-legged waddle. I could almost hear a voice behind me yelling ‘Run, Forrest Run!’

After I had done a couple of laps I noticed that as well as my son there were two other young children following me. I started waving my arms to shoo them away but it only seemed to make them more determined. Soon other children began to join in until it became like the scene in the Rocky movie where he goes for a training run and hundreds of children follow him like a swarm of persistent bees. The park was full and more than half the kids seemed to be chasing me.

I became aware that many of the parents were watching me now. Some were amused, some confused, some bemused and some plainly horrified

I started to worry that they might see me as some sort of sinister Paedophile Pied Piper who was going to run straight out of the park and not stop until I had led all the poor unfortunate children to my secret cave.

I had to bring the situation to an end. I was knackered. I was being followed by a group of unknown children. I looked downright stupid.

I thought the best thing to do would be to collapse there on the grass in a comic simulation of mock exhaustion. The mummies would all applaud my wit and the children would understand that the game was over and go quietly about their business.

It turned out not to be the best thing to do.

As I went down onto the grass my son followed, without missing a step, by leaping on top of me. He must have seen it as a continuation of our wrestling games.

The rest of the kids, whether innately or by decision I couldn’t tell, did exactly the same thing until I was buried under a pile of laughing pre-school children. For a moment I couldn’t get a breath and panicked, considering that this was not the way I had imagined it all ending.

It got worse. Encouraged by my son who views the dishing out of extreme violence as a way of measuring affection, the children started to batter me. I reckon I could have taken any of them on their own but as a group they were irresistible. One small red-haired child, still in nappies I noticed, started to kick me repeatedly in the face. Someone else was behind me pulling my hair. I felt teeth on my shoulder. One little girl was ripping up handfuls of grass and attempting to shove them down my throat. I screamed for mercy.

The ordeal seemed to go on forever but I’m sure I’m reality it was no more than 90 minutes or so. Then a couple of the mummies moved over and summoned their kids. I heard the mother of the red-haired child ask him if he was alright.

Dazed and beaten I climbed back to my feet. My son was there waiting. His face full of innocence and hope.

‘Daddy, did we beat the world record?’