I don’t know what it is about the art and antiques business, but it certainly attracts some strange and rather wonderful characters, many of whom delight in turning up at auction in person.

There is a tale of how, many years ago, an eager young man on the front desk at one of our leading auction houses was horrified to see a shambling wreck of a figure shuffle through the front door and start to make their way to the saleroom during a view.

Eager to save his employers and their well-to-do clients the embarrassment of having to rub shoulders with this tramp, he shot round the counter to intervene, politely but firmly escorting him back the way he came. Imagine his surprise when, having reached the front entrance, the elderly man was greeted by the doorman, who tipped his hat, adding: “Leaving so soon Your Grace?” Far from being an undesirable who had come in off the street to escape the cold, the aged eccentric was, in fact, a well-known landed duke and one of the auction house’s wealthiest patrons.

It is a lesson well learned in our industry not to judge a book by its cover. Somehow, the fine arts and first class craftsmanship attract the more singular characters of society – and often they are the ones with the deepest pockets, so a smile, friendly greeting and polite welcome is a prerequisite for all.

A car number plate, a luxury yacht, a gym sweatshirt, a copy of The Beano and a chesspiece. What do they all have in common? They are all items that have made the news over the past week or so either because they have sold at auction or are soon to be sold.

This snapshot of the variety of sought-after lots that can appear at any one time is one of the best illustrations I know of why this is a great business to be in, whether as an auctioneer, specialist, dealer or private collector.

Take the yacht, for instance. The 85ft motor yacht, named Caviar, had once belonged to a criminal and had been auctioned off by the police after being left abandoned for some time in Southampton. Although valued at several millions pounds, a young family snapped it up for just £66,000. Ok, they then spent a further £300,000 doing it up, but this auction opportunity gives them the chance to live the dream in considerable style as they set off on a round-the-world trip.

Renamed Juliette after the couple’s young daughter, the yacht will eventually return to these shores, providing the family with a substantial uplift o their original investment.

What is art? It’s a question whose answer has evaded us for centuries. Attempts to define it clearly have never worked because, like the wind, we can see and feel it all around us, but can never quite pin it down.

Frustrating as this might be, mostly we know art when we see it; this elusive quality is what makes it so fascinating and versatile. In turn, that means that art is forever reinventing itself and can appear in the most surprising forms, especially these days when fairly mundane items created for a different purpose are remodelled or redefined as art – folk art, for instance.

A good example of this is the EU entry gate sold at auction last year when the entire contents of Terminal One at Heathrow came up for sale. The hammer came down at £1000 and no one thought any more about it until the Royal Academy Summer Show opened a couple of weeks ago and there it was, transformed by Banksy into a new work of art combining humour and political statement. The gate itself looked almost the same as it had done when auctioned off. Banksy had added a shutter and painted the words Keep Out on it, rendered as Keep Ou because his signature rat had removed the T to use it as a hammer to break the padlock at the bottom. Not to everyone’s tastes, maybe, but with Banksy’s transformative touch, this work of art will be worth a great deal more now than its original auction price.

In many ways, what must be one of the most astonishing auctions of recent years has just taken place. The lot in question? The gun with which Vincent Van Gogh is supposed to have killed himself.

The astonishing thing about it is that even the auctioneer selling it was clear that no evidence exists to show that this was the actual gun, yet it made the equivalent of £144,000.

The troubled artist died a few days after walking into a field near Auvers-sur-Oise and shooting himself in the chest. It was July 27, 1890. No one knows what happened to the gun, but in 1965 a corroded revolver was dig up in a field near the chateau where he had been staying and tests indicated that it had been in the ground for between 50 and 80 years – so about right.

That’s as far as it goes, so the buyer was acting in faith, just as pilgrims making their way to shrines that house anything from St Catherine’s finger to a thorn from Christ’s Crown of Thorns are also taking it on trust that these relics are genuine.

Ordinary everyday items acquire a unique symbolic status when they have been touched by inspirational figures like Van Gogh, who will remain forever out of reach themselves. Akin to holy relics, they hold a special attraction for bidders at auction.