The traditional story told about the first world war is that it changed everything: that it was the end of the old world and the beginning of the modern age, and that art and poetry could never be the same again. So it is refreshing to find, not far into Lance Sieveking’s amiable and haphazard memoirs, the claim that ‘I didn’t realise it at the time, but in 1919 I was a comparative rarity: a complete young man, a man with two arms, two legs, two lungs, two eyes.’