We know that risk occurs in investment, in gambling, in skiing, in Formula One. It also occurs in everyday life. Sometimes I start an answer to a question and I find I have taken too great a risk thinking I will find a way to articulate something rather vague that I had in mind when I started my amswer. This happened to me a few days ago when I was answering a question about history in front of a group of people. In my mind I had the word acoustic and I thought I could find my way through to a full answer with just this word. What I wanted to say was that something that seemed one way many years ago often seems different today because the acoustic had changed. What seemed moral in 1938 now seems thoughtless. There are all kinds of topics where this applies: racism; sexism; classism; ageism. But also the basic words and assumptions that people had and now have. The acoustic has changed; we hear things differently. Unfortunately, the only example that came into my head as I was scrabbling around for my words was Top of the Pops and the way the DJs in the 1970s were often surrounded by a collection of underage girls. What seemed part of normal healthy celebrity behaviour at the time now seems unpleasant and creepy. A moment of inadvertance had me seeming to sympathise with the likes of Jimmy Saville. I had taken too big a risk in thinking I could plot an answer on the hoof and had to retreat into a safe place. Jacob Rees-Mogg, not I admit my favourite person, has just fallen foul of this principle by letting his mouth run away with him and mentioning in the same breath a lack of common sense and the victims of Grenfell. This risk of an unprepared response may well cause his downfall.