As a young man searching for a way to make a living in Paris, Antoine Watteau briefly tried his hand at engraving fashion plates. He seems to have had a natural affinity for cloth and drew its folds and creases with such apparent ease that you can almost feel the slipperiness of satin and hear the rustle of taffeta as it moves with the body. This was just as well, since he didn’t attend the Academy where students did life drawing and learned anatomy.

I’m in an exhibition of ancient artefacts from Afghanistan, all from the National Museum at Kabul, but I may well have stumbled into the wrong room at the British Museum. I could be in the BM’s Hellenic section of Greek art, or, taking a few steps to my left, the Egyptian rooms. But then again… here are some sensual sculptures of curvaceous semi-clad women from India (main picture), while a little further on there’s a Chinese hand mirror and some boot buckles, the latter with Chinese dragons whose wings are of turquoise.

An artist as inventive and as protean as Picasso, and one who ceaselessly absorbed influences throughout his life, will inevitably present an ever-changing face to the world. Hence, we have an apparently inexhaustible supply of exhibitions devoted to him.

The latest exhibition from Beirut-born, sometime Turner Prize-nominee Mona Hatoum – best known for sending a camera through her inner tubes and projecting the results – explores themes of displacement and geographical and political tension. I know this because since I signed up to review it a fortnight ago, invites and reminders concerning this exhibition "exploring themes of displacement and geographical and political tension" have been hitting my mailbox with hectoring insistence.

The National Gallery has done it again: a small but perfectly formed exhibition in their little Room 1, now a by-word for intelligent show-making. Something new, something revelatory, something profoundly beautiful – what more can the gallery-goer ask? The Ashcan School is not widely known outside the USA, and I can think of no better introduction than this dozen-canvas-strong showing of some of the highlights (and, it must be admitted, a couple of low-lights as well).

If you’ve seen pictures of the Ballets Russes, then you’ve seen Hoppé photographs. But then, if you’ve seen any society pictures from the 1920s and 1930s, then you’ve seen Hoppé. And famous writers. In fact, for portrait photography in Britain between the World Wars, you can pretty well bet the photo is Hoppé’s. But what's so good about this new exhibition is that it shows a side to Hoppé that is much less well-known - the street-view. And these photographs are thrilling, in form as well as content.

Jan, or Janin? Gossart, or Gossaert? Or Mabuse? After a mere five centuries, we haven’t settled on a name quite yet (even for this exhibition: at the Metropolitan Museum, the same show spelt it “Gossart”). We don’t know where he was born, although Maubeuge, then in Hainault, now in France, is the best guess, hence “Mabuse”. His birth date too is a mystery: the Grove Dictionary of Art suggests 1478, while the National Gallery just shrugs and gives us “active 1503”. What is in no doubt, however, in this very model of an exhibition, is that Jan Gossaert represented not merely one of the peaks of northern Renaissance art, but that, in a constantly surprising career, he also synthesised great swathes of the Italian art world, both classical and Renaissance, creating something new and hugely potent.

Louise Bourgeois died last year at nearly 100, a revered figure: survivor of the Surrealist movement into the 21st century, a pioneer of autobiographical expression, whose fame came only late in life. Tracey Emin, by contrast, found fame early, coming to the attention of the general public in Charles Saatchi’s Sensation show at the Royal Academy while she was still in her thirties.

Does watercolour painting suffer from an image problem? Do you think of the wild, vaporous seascapes of Turner, or Victorian ladies at their sketchbooks dabbing daintily at wishy-washy flower paintings? Do you associate the medium with radical innovation or with staid tradition? And would Jackson Pollock have appeared quite so heroic flinging thin washes of watercolour around instead of viscous oils?

After writing about a recent survey of French artist Philippe Parreno at the Serpentine Gallery last year, I found myself wondering about his collaboration with the Scottish artist Douglas Gordon. In 2006 the two artists made the acclaimed film Zidane: A 21st Century Portrait, and while Parreno’s skills as a film-maker were pretty evident from that first UK solo exhibition, Gordon’s talents must surely lie elsewhere - that is, outside the frame. Neither technically ambitious nor visually seductive, his films are not even meant to be seen in their entirety, certainly not his 1993 24-hour Psycho, which is simply a frame-by-frame re-presentation of the Hitchcock classic.