Tucked away in the back of a Covent Garden restaurant, fresh from a fag in the bitter cold, Sir Michael Gambon looks like someone drew a caricature of Sir Michael Gambon, and got carried away. The wild trolling hair on the back of his head gives way to an unabashed half dome at the front. Beneath it, beyond the hyperactive eyebrows, deep folds of cheek and jowl arrange themselves to suit the prevailing mood. I had expected the prevailing mood to be one of disdain. Gambon hates being interviewed. Hates it. But today he is warmth personified. His eyes sparkle, his handshake is comprehensive. He is delighted to be here. Either that or he’s an excellent actor.

Still, there might be a problem. Gambon’s memory