Aren't reputations strange things? Frequently based much more on fantasy than fact, they are often completely out of our control, and - whether good or bad - often ludicrously undeserved.

These thoughts were triggered by a patient who had just registered with us. He had a wealth of medical problems, and was going to be someone I would get to know well over the coming years. At the end of the consultation he said: ‘I hear you're a pretty ace guitarist too.'

This came so far out of left field that, rather than just accepting the compliment or deciding to get my hearing checked, I asked him where on earth he had heard that.

‘Well,' he said, ‘they told me in the pub that you used to put on a Christmas concert with your guitar.'

The truth was much more straightforward. Some 20 years ago a local charitable organisation used to ask me to join their pre-Christmas dinner dance to take part in the cabaret. It was an example of the classic British tradition of getting prominent people in the local community to make absolute idiots of themselves in public. Indeed, this was a concert so lacking in sophistication that it made the average medical school Christmas show look truly professional. It gave amateurism a bad name, and I cringe to look back on my contributions.

And yes, on a couple of occasions I did clutch a guitar. I think at one I was also dressed in an all-in-one pale blue Elvis Presley style jumpsuit, which is a thought that I don't want you to ponder on for too long. And at another I did a version of Paddy McGinty's Goat, which featured Paddy McGinty trying to talk the local GPs into giving him a sick note - as in the stupendously witty and satirical ditty of Paddy McGinty's Note. That's another thought I don't want you to dwell on. Thank the Lord that simple video technology or YouTube hadn't been invented then, or I suspect my subsequent career would have been toast.

But clearly the mythology of the town's folk had rewritten the vague memory of me holding a guitar somewhere sometime, to me being a guitarist putting on a concert. Little could have been further from the truth. But to argue will inevitably sound like protestations of false modesty. Move over Eric Clapton.

Though the reputation that probably did me the most good was way back when I was doing my very first house job. I was working at a very small hospital, now long demolished, and was one day summoned urgently to the outpatients clinic where a very, very senior consultant was all of a panic as one of his patients was having a convulsion in the waiting area just outside his consulting room. Treating convulsions was not in his repertoire. He needed expert help. The only expert help available was the 23-year-old me.

When I arrived, it was pretty clear to me that this man wasn't having a convulsion at all, but was hyperventilating with tetany. So I took a deep breath - not too deep, mind - asked for a paper bag, and held it over his face to the consternation of everyone around. And, thank heavens, the shaking stopped and the man rapidly came round.

All this happened just outside the hospital's telephone exchange, where the operators watched every moment of the drama, and then went into overdrive in their role as central source of all gossip in the hospital. ‘Did you see what that new doctor did there?'

And my reputation was made for six months. Pity it couldn't last into the next job. But that's quite another story.