LET US BE GRATEFUL FOR SMALL MERCIES

A friend of mine has just had a knee replaced. She's only been out of hospital a few days and I called around to see her on Friday. Despite all the pain she remains smiling and optimistic, sitting on the sofa with an unusual piece of equipment under her operated-upon leg.

This is a surfboard and placing the bad leg upon it she rocks it back and forth, easing the joint.

She calls it her 'bad' leg because it is worse than the other. Though that knee too needs replacing and is very painful. She has been on painkillers for her knees for some time, though she is only in her mid-fifties.

I ask why she didn't have both knees done at the same time and she answers that the pain would have been too much. Which immediately made me ask 'Really?' Would it?

If you cut your finger, it hurts. But if you cut two fingers at the same time the quantum of pain isn't doubled. It is as if you get 'cut finger pain' regardless of how many fingers you cut. It just comes in different places.

Peter Cook and Dudley Moore illustrated this once in a satirical sketch on acupuncture. Peter Cook imagines Dudley Moore as a man with a pain in his elbow. 'So they stick a needle in your leg,' says Peter. 'And then you forget about the pain in your elbow and worry about the pain in your leg. And then they stick another needle in your bum to take away the pain in the leg......'

I can't obviously speak from experience but I can't imagine there being very much extra pain from two simultaneous knee operations and, were it me, the thought of having to go through the pain and immobility a second time would be insupportable.

My cousin in Alberta, who was 75 at the time, had both his knees replaced at once and was riding a horse again in two weeks. But then he was a tough old frontiersman - or liked to think himself so - and a doctor to boot.

Still, in pain or not, this friend of mine is very good at drawing you out and so I found myself, before I realised it, moaning to her, quite shamefully, about some little irritation that the day had brought.

Most of my irritations resolve themselves into a vague feeling of not having achieved as much as I feel I ought to have achieved. I know this is nonsense and I equally know that it is a deep-rooted seed planted by my parents who were never satisfied with anything I did. It is a corrosive leit-motif to my life, but I fall for it every time Mr Black Dog comes calling. Even when I am with someone sitting smiling and joking who has just had a knee replaced.

When I got home I opened the newspaper to see the smiling face of Sue Townsend, the author of the best-selling Adrian Mole diaries - who is, as it turns out, exactly the same age as me.

She is now registered blind, having lost most of her sight. Her health has deteriorated in other ways too and she is now looking for a kidney transplant.

Of course I should have loved to receive the recognition that comes from penning an oeuvre as successful as Adrian Mole (though had I done so Mr Black Dog would have just told me that this wasn't a serious enough book to count).

I imagine Sue Townsend's success is not in any way correlated with her health. But if I had too choose between her life and mine I am quite sure that health would trump success every time.

Which is yet another illustration of why we should be grateful for small mercies and think positively. Success and failure, as Kipling wrote, are mere impostors.