It’s no good telling the British they will be worse off: prices higher and jobs lost, petrol more costly and holidays unaffordable. Above all, don’t say it will be like going back to the 1970s. Astonishing though it is, there is a big constituency of people who look back at that era of struggle — coin-operated electricity meters, the stink of damp wool, unheated homes and dreary food — with fondness.