Picture the scene—a Friday evening. For once in his life, he is actually home in time to get ready to go to the big bash in the local orthopaedic consultant's house. She has organised the babysitter who is already there, the kids are happy, everyone is dressed up, it's going to be a wonderful evening. He drives there (she'll probably drive home, but anyway …).

They can tell they are getting near to orthopaedic country as they start to see the odd Land Rover Discovery parked, and she helpfully points out—“Look, there's a parking space coming up ……You've just gone past it. That would have done wouldn't it?” “No, no, no” he says. “There will be something nearer further on up.” Of …