My older brother sussed me out when we were both quite young. When he wanted my parents’ attention at night without calling for them himself, he would simply lean across from his bed to mine and whisper “Noddy is an idiot”. The fuss caused by this slander against Enid Blyton’s hero would bring Mum and Dad running.

Their sage counsel — which, come to think of it, they should have followed themselves — was simply to ignore it. But I found this advice almost impossible to follow. And I still do.

I’m well aware that in politics you rarely persuade people. When you start arguing about some falsehood, you often succeed only in reinforcing your interlocutor’s sense of how right they are. During the European