I feel bad that he didn't come to terms with this sooner, but it's his own fault. Laughing, smiling, looking forward to sunny days - what was he thinking? Sooner or later that kind of attitude just has to take its toll. Positive people are so busy smelling the roses they never take time to worry. Luckily, I can help. I've been thinking about illness, dying alone and being infirm, all my life. How to live with uncertainty and negativity is a skill that comes through years of practice. I've told him he can't expect to become a well-adjusted negative person overnight. I've worked pessimism into my schedule and got into the habit of embracing it. Like brushing my teeth. It's become second nature.

Take disease - I worry daily. I know it's only a matter of time before something gets me. The other day an elderly woman said to me: "I never expected to get arthritis." I was amazed. Who doesn't expect that? If my toe aches it's the very first thing I think of. Then I find out it's a bunion - but at least I've got the worst-case scenario out of the way. Once you accept it's downhill, there's much less disappointment. I feel sorry for people who never think about old age, because when it hits it's devastating. _The only way to avoid it is to wake up in the middle of the night with a blinding flash of realisation and then have a fatal heart attack immediately. Then it's not a big deal. You've only worried about it for a few minutes. I know when I'm older, I won't be in for a shock. I don't want to get out of bed most days, so I'm used to infirmity. My father, on the other hand, has always seized every morning - excited to start the day. It's not natural. When he is down, he feels like there's something wrong. I tell him: nothing is wrong. It's healthy. It's just that he never let things bother him before, so now there's a cumulative effect. My advice is to let things bother him a little bit more every day. Once he's built up a tolerance, I can show him a routine. First, sweat the small stuff - such as who hasn't called back and what that means - early in the day, so that it doesn't keep you awake that night. Then, just before you go to sleep, worry about the big stuff you can't do anything about. Things that are out of your control like when you'll die, where, of what, and how long it will take, etc.

After ruminating about this for an hour, it gets so exhausting you fall into a deep and satisfying slumber. The next thing you know, you wake up refreshed, ready to start a fresh day of worry. Most importantly, he has to remember this is what life is about. It happens to everyone. And five years from now, when he's three times as anxious, he's going to wish he was as miserable as he is now. These will seem like the good days. He needs to settle in and enjoy it.