I wonder who invented car boot sales. Whoever it was should be given a prize. And that prize should be the opposite of the Nobel Prize, perhaps the Kick-In-The-Head Prize.

Because if anything was designed to demonstrate the basest and most ragged of what human nature has to offer, it is the car boot sale.

Before Sunday, I had always fancied that a top-notch way to dispose of some of the rubbish that had attached itself to me over the years, barnacle-like, would be to flog it off from the back of my car. Grateful punters would tussle good-naturedly with each other to get their mitts on my unwanted DVDs. A rosy-cheeked old lady would, perhaps, clasp my hand and praise the Lord that I had the dolly her sickly grandchild had been craving for months.

I was a naive idiot.

I turned up and was shown the way to my pitch. As I emptied my boot of its booty, I was suddenly aware of a presence behind me.

“How much for the computer monitor?”

“Erm, tenner?” I offered lamely.

“Give you a fiver for it.”

“All right,” I said. The man appraised me quizzically, handed over the cash and picked up the monitor. “Hang on a second, does this thing work?” he asked.

“Yes,” I said. I was almost sure of it. It had been 18 months since I’d last used it, but it worked then. Satisfied, my first customer walked off. But his quizzical look disturbed me.

No, he couldn’t have done? Surely he didn’t expect me to haggle. Must have been a one-off. Still, that was a fiver. Only a quid left and I’d be able to pay my entry fee.

Or would I? All around me the other traders were breaking out the trestle tables. Trestle tables? Nobody mentioned trestle tables. It’s a car boot sale, not a trestle table sale.

No, wait. The woman next to me didn’t have a trestle table. “Phew,” I thought. “I’m not going to look like a complete amateur.” Then she constructed a clothes rack, hung a billion shirts on it, then took out a trestle table, covered it with plush black cloth so as to show off her fine range of brown and grey men’s knitwear, and strapped on a bumbag full of change. “Ralph Lauren shirts, only £2,” she called out. Suddenly I felt like Church Street when Liverpool One opened.

I was snapped out of self-pity (“There’s no way her husband could have had that many brown and grey jumpers. She must have ram-raided Benetton”) by a customer, an actual customer.

“How much for the Bob the Builder toys?”

“£1.50 each, as they’re unopened and still in the packaging. Tell you what, a fiver for the four.”

“I’ll give you £4.”

I didn’t believe it. I’d already knocked myself down, I was beggared if I was going to haggle. This wasn’t a souk in Morocco. I didn’t have the finest silk and spices in the back of my Nissan. I was just flogging off old guff in a car park in Childwall. I decided a passive stance would at least make the customer feel a bit guilty. A small victory.

“Erm, OK.”

Then she appeared. My rosy-cheeked old lady. At last! Smiling, she picked up a dolly.

She held it, stroked its hair, examined its fine clothes. Then she looked up its skirt, wrinkled her nose, dropped it into the pile and walked off. I have no idea what she was looking for, but she clearly didn’t find it.

Disconsolate, I blew most of my profits on a hotdog.

Twenty-two quid I’d made by the end of the five-hour ordeal. But that had to be set against the irretrievable loss of my faith in human nature and my understanding that people will haggle over the price of a 30p girl’s dress.

I will never laugh at the losing side on The Apprentice again.