"You have the nerves of an 18-year-old." Of all the things I could wish to have of an 18-year-old, this would not be top of the list. How about the skin of an 18-year- old? Or the energy?

He then showed me another x-ray to show what a nerve in a normal tooth for someone my age should look like. The line was thin, barely visible. Mine looked like the Yangtze river. "Usually, the nerves recede as we get older," he said. "But you're an unusual case."

For two weeks preceding this visit, I had been unable to chew on the right side of my mouth. All my life I've taken chewing for granted. Chomping away on carrots and granola; never suspecting that I was just one almond away from a lifetime of mashed potatoes and soup.

And suddenly it happened. The electrifying tenderness of biting down and feeling like I'd been shot. I went to the dentist. He told me not to worry. But he always says this, and so of course I worried he wasn't taking me seriously.

I remembered all the times I'd moaned about a cavity; how could I have used up my sympathy on a filling?

He removed my old crown, placed a temporary on, and then came the dreaded words: root canal. In the past, when I've complained about something, my friends would roll their eyes and say: "It's not root canal." What would they say now? It was almost worth getting the root canal to find out.

The reaction from my British friends was very different to that of my American friends. Most of the Brits I spoke to regarded root canal as slightly more eventful than napping. It happened on a lunch break and was not a big deal.

My American friends spoke about root canal as though it was open-heart surgery. Kim said hers took five hours, "and there was blood everywhere". On the positive side, she noted, my root canal couldn't possibly be worse. That was the comforting part? That I wouldn't emerge covered in blood?

I couldn't understand how in London a root canal could happen at lunch, but in New York it would take three visits. Everything in New York is more complicated. And it requires a specialist. Now I won't just have a dentist, I'll have an endodontist. Soon, I might need a periodontist for my gingivitis and then I can celebrate turning 90.

Two weeks later, back at the dentist, it was a scene from Marathon Man. He decided to remove the crown without numbing me up so I could test the bite. He leant in with what looked like pliers in his hand. I screamed so loudly, I could hear his other patients instantly rescheduling their appointments. Worse than the pain was the anticipation that in the next second it would be 20 times worse.

The real test came the next day when it was time to see if I could bite down without it being agony. Just as I was preparing, the phone rang. "Can't talk," I said. "About to chew." I hung up. I had to focus. And then, with a make-believe drum roll in the background, I bit down on a piece of apple. Slowly, at first. But I could chew. I was filled with joy. Seconds later I was filled with regret. Because, after all the discussions about root canal, in the end it turns out I wouldn't even need one. Which means next time, when it happens for real, nobody will care.