What worries you about getting older?

I don't want to be called a senior citizen, I feel like a spring colt. I don't want to be called a has-been, because there's things I want to do in life. But, I've been there and I'd say, "Don't let the bastards get you down." And they don't anymore, I don't talk to them anymore, so they don't get me down. I've got my family, and I've got so many blessings that I don't think I've earned, that I'm a very happy man.

I saw them recently on their morning walk, and they caused me a pang. I have always wanted a pug and now I can't have one, because buying a puppy when you are too old to take it for walks is unfair. There are dog-walkers, of course; but the best part of owning a dog is walking with it, enjoying its delight when it detects the signs that a walk is imminent, and its glee when its lead is unsnapped and it can bound off over the grass, casting cheerful looks back at you from time to time to make sure that you are still in touch.

I cry a lot because I miss people. I cry a lot because they die and I can't stop them. They leave me and I love them more. ... And so it's what I dread more than anything is the isolation.

I was looking at ageing in action, in black-and-white MRI pixels, death and dissolution foretold, and already partly achieved. My 70-year-old brain was shrunken and withered, a worn and sad version of what it once must have been. There were also ominous white spots in the white matter, signs of ischaemic damage, small-vessel disease, known in the trade as white matter hyperintensities – there are various names for them. They looked like some evil pox. Not to put too fine a point on it, my brain is starting to rot. I am starting to rot. It is the writing on the wall, a deadline.

Forgetting the wonderful memories I have got from throughout my life. Three years ago, I was diagnosed with dementia.

Possible dementia.

Am I enjoying it too much to find out?

That my nose and chin will touch.

Not being able to perform adequately.

Becoming doubly incontinent.

Not being able to fend for myself and being a burden to others.

Learning lines.

I go in every day to the office. I don't accomplish hardly anything. I mean, in terms of – it just takes me way longer to do things. And Greg is so good. It was kind of embarrassing how good he is, because he has covered – you know, we've got about 200 businesses within Berkshire, you know, that came about, and I can't name the manager's names or their wives names, or – and I haven't seen them, you know, in a long time. It's easier just to write the letter once a year and kind of do my own thing. Greg covers more ground in a day than I would in a week, even when I was at my peak, let alone my present condition.

Getting even older.

Not to be able to do the things that you take for granted, like running up the tube steps or going somewhere under your own steam.