I was looking through an address book I'd used until I was 25, and began to realise that amongst my friends (as opposed to colleagues or relatives) listed there, circa 50 per cent are now dead. Death has been from a variety of causes: e.g. terrorist bomb, suicide, alcoholism, cancer, hypothermia (i.e. it's not that we are all part of a disease cohort). Things aren't all that much better for my friends who survived - half of them have, or have had, very serious illnesses or similar, such as kidney disease, suicide attempts, severe sight loss, etc. Friends made after 25 seem to be all okay (I'm now aged 42). Has anyone else had such a deadly effect on their friends?