What we know; what we don't, what we lose. By Louisa Young

The house I live in was built in the 1880s. I know the development was called the Orchard Estate, because it was built in an orchard. The bluebells which sprout in all our gardens are no doubt remnants of a bucolic past. I know the plaster was mixed with horsehair, because I found it when we took a wall down. I know the man who used to live here had one arm, and fought in the Second World War. That's not where he lost his arm though: he lost it to a fishing accident. After the war, he was using hand-grenades - stolen? Black market? - to blow fish out of the water, and blew his own arm off. He died, twenty years ago, in my kitchen.

My father's father, Hilton Young, had one arm. He lost his during the raid on Zeebrugge. When he was fixed up, he reported to the Admiralty and they said no, no, you've done enough, whereupon he looked out the window towards Trafalgar Square and said: 'I can see a chap, from here, who served the Navy well enough with one arm' - or words to that effect. So they took him back, and he commanded an armoured train across Russia.

I never quite believe these stories about my ancestors. How can they be true? My relatives (including me) are all terrible story-tellers and after-dinner exaggerators, bemusers of small children with tales of newts in the sink, seals in the sidecar, conductors in tutus dancing on the piano. According to them, Great Uncle Geoffrey (below) - brother of the lost arm (above) - had climbed the Matterhorn with a wooden leg, and carried a spare with him - his best - for a photo at the top.

So I was reading Wade Davis's very interesting book Into the Silence: The Great War, Mallory and the Conquest of Everest. There on page one is Geoffrey Winthrop Young - and it's all true. While at Cambridge, he did write 'The Roofclimber's Guide to Trinity', about how to negotiate the rooves and turrets of the university. He did climb the Matterhorn, with his one leg. His prosthetic leg, it turns out, was of his own design. No mention is made of the spare, but I learned how he lost his own flesh-and-blood leg. Too old for active service, having been a reporter on the Western Front since the first days of the war, in 1915 'he abandoned journalism to serve in an ambulance unit of his own creation. First in Flanders, and later in Italy, Young and his colleagues would rescue more than 100,000 wounded soldiers, before he was himself cut down.'

I hadn't known that. I knew his widow: her name was Len. Other people thought it funny to have an aunt called Len. I didn't know Len was a man's name. At university I met a boy who also had an aunt called Len. We were enchanted by the co-incidence, even before we found out it was the same Len.

There was a story about the three Young brothers: that Hilton lost his arm; Geoffrey his leg, and Georis his head - he came home a Communist.

They all wrote books, pamphlets and poems, and had full and interesting lives after the war.

I can write, on a good day, in my horsehair house, built around the time they were born. But I don't know when I am going to help save 100,000 lives. Or take charge of an armoured train, or be brave enough to come back Communist. Or climb the Matterhorn. Even with two legs. I don't know how on earth I can live up to these forefathers. I wish I could tell them how much I love and honour them, and that my only inclination towards religion would come from the possibility of meeting them.