Admittedly, it doesn't take much to get me over-excited these days.

Three cars going past my drive in an hour can do it. A new face in the village can lead to frenzied speculation for days. Most of the time, fortunately, my son does not bear witness to the batty old woman his mother has become.

Unfortunately, his week's holiday this summer coincided with a display of overexcitedness so inappropriate even I am a touch ashamed. Pierce was both appalled and shocked enough to remove himself from my presence, although he returned when I solemnly promised to behave.

They may not have understood the language but the group of French urchins scattered around us grasped the import of our "discussion". Tittering, they gave me looks of triumph as I pulled myself together. In my defence, can I say I was the victim of a deliberate attempt to stir up passion, the victim of a powerful force that sweeps through France once a year?

The Caravan is the fast, chaotic parade which precedes the riders of the Tour De France. A 45-minute publicity stampede of the major advertisers who use floats, cars, pretty girls and loudspeakers to whip up the crowd in advance of the peloton.

One had huge jumping horses and jockeys, another a giant bike and rider; naturally Le Coq Sportif had enormous cockerels wearing the yellow jersey; the Evian girls sprayed us with a fine mist but the Vittel lot chucked bottles of water at us. Luckily the baguette float girls threw only vouchers.

As each passed, music blaring, people shouting, we banged the plastic barrier and shouted: "Allez. Allez," adding our own beat to the mayhem, waving our arms to be thrown a prize and shouting: "Moi, moi." (Or was that just me?)

The prizes were tat: key-rings, cheap caps, vouchers, fridge magnets, sweets and even cakes – nothing to fight over at all. Oh, but fight they did. We – ah, the shame – did.

When the bottle of Vittel bounced off my shoulder I bent to pick it up. My hand hadn't got near it before a swarm of five, six and seven-year-olds scrabbled at my feet and snatched it away.

The second time – the luminous key-ring – I was ready. A tiny brown hand beat mine and the four-year-old ran to pop it in her already bulging goodie bag.

The third time – the cotton cap I really, really coveted – landed against my chest before starting its slide down. A boy, maybe 10 years old, grabbed it. I grabbed him. "It's mine," I hissed. "I got it."

Life flashes in a second. I realised the boy had a large father; I saw Pierce turn his head in horror before walking quickly away, and I recovered enough to laugh manically and drop his arm.

Resolutely, with Pierce's eyes fixed on me, I ignored the rest of the rain of goodies until one dropped at my feet and I stamped a foot on it; bending victoriously toward the crouching infant, whose hand was outstretched. Her lips quivered and she shouted: "Papa." Quickly I snatched the Kitty magnet and said soothingly: "It's for you. Only a joke. Really." Pierce put an arm around my shoulders and moved me back to the barrier. "Will you please behave?" he said. "The riders will be here in half an hour."

We were in Lafrancaise, a bastide town 40 minutes away. Bradley Wiggins, barring accident, was on course to win le Tour. Just two weeks earlier, after months of gruelling training, Pierce had completed the five hardest stages of the tour for the William Wates Memorial Trust. He was determined to see the professionals.

In the Jura and the Alps he had ridden 485 miles and done 50,000ft of climbing with a top speed of 47.7mph. His determination and dedication to completing the stages both astonished me and made me very proud. It also gave me a new respect for the riders of the Tour De France plus a knowledge of all things Lycra – far more than I ever wished to know.

So I stood quietly by the barrier, waiting for the sound of the cyclists. Hundreds were around us; many, surprisingly, with Union flags. The motorbikes of the press and the camera crews sped by, the whirr of the helicopters overhead announcing the imminent arrival of the pros. It was strangely emotional.

As they passed, perhaps four inches from our touch, the pounding reached a crescendo. I jumped back as handlebars almost grazed the plastic barriers. My vision could barely cope with their speed – the glimpse of Wiggins's yellow jersey was just that – and then they were gone, a wave of wind and bodies cycling in a frightening if controlled bunch.

The crowd let out a sigh. I grabbed Pierce's arm, still shaking with the force of it all and momentarily disorientated. On the ground lay a discarded cap. The child and I locked eyes. I nodded for her to take it. She picked it up and handed it to me. "Wiggins. Bon." n