'Dr Livingstone, I presume,' said Henry Morton Stanley; his indomitable will had driven him headlong across jungle, desert, mountain and river, and he bestrode Africa like a colossus.

But the legend does not tell the whole story, for the legendary adventurer had something further to say: 'By the way, doc, I have a bit of a cough; could I have some antibiotics? And what about an X-ray, my leg's giving me jip?'

We can't escape it, can we? Once a doctor, always a doctor, ours is a high and noble destiny, and I still remember the first time I put on a white coat and hung a stethoscope around my neck; a bit like the first time I had sex, although not as sweaty and with less protection, and with more ridicule from those more experienced; je ne regrette rien, I say, good sex may be great, but bad sex is still good.

But if you buy the farm, you get the Indians, and the same moral code that ordains we stop at road traffic accidents also compels us to listen to strangers on the train recounting how they discovered an ingrowing toenail protruding from their scrotum; we can never entirely lay down our onerous responsibilities.

Once you become a doctor, everyone else in the world immediately falls into the category of 'patient'. Wherever there are sick people there will always be doctors, with the unfortunate corollary that wherever there are doctors, there will always be sick people.

My auntie Mary was a simple country woman who earned a living off the land, blackmailing farmers, smuggling cigarettes and ambushing insurance salesmen, and to her, doctors were different from everyone else, a kind of aristocracy.

I remember telling her I was going to become a doctor and that I was off to medical school for six long and hard years; as she was fanatically religious, I was careful to omit the all-night drinking and carousing and rogering that this would entail.

I could see her thinking it over and she went away and came back a while later and said: 'And can you become a doctor just like that?'

• Dr Farrell is a GP from County Armagh. Email him at GPcolumnists@haymarket.com.