This excerpt was first published in The Straits Times on Aug 11, 2013.
My daily routine is set. I wake up, clear my e-mail, read the newspapers, do my exercises and have lunch. After that, I go to my office at the Istana, clear more papers and write articles or speeches.
In the afternoons and evenings, I sometimes have interviews scheduled with journalists, after which I may spend an hour or two with my Chinese teachers.
I have made it a habit to exercise daily. At the age of 89, I can sit up and I do not need a walking stick.
When I was in my 30s, I was fond of smoking and drinking beer. I quit smoking because it was causing me to lose my voice at election campaigns. That was before medical research linked smoking to lung and throat cancer, among other things. Oddly enough, I later became hyper-allergic to smoke.
The drinking gave me a beer belly and it was showing up in pictures appearing in the press. I began to play more golf to keep fit, but later on turned to running and swimming, which took me less time to achieve the same amount of aerobic exercise.
Now, I walk on the treadmill three times a day - 12 minutes in the morning, 15 minutes after lunch and 15 minutes after dinner. Before dinner, I used to swim for 20 to 25 minutes.
Without that, I would not be in my present condition physically. It is a discipline.
I continue to make appointments to meet people. You must meet people, because you must have human contact if you want to broaden your perspective.
Besides people in Singapore, I meet those from Malaysia, Indonesia, and, from time to time, China, Europe and the United States.
I try not to meet only old friends or political leaders, but people from a variety of fields, such as academics, businessmen, journalists and ordinary people.
I have cut down on my overseas trips significantly, because of the jetlag, especially when travelling to the US.
Until 2012, I was still travelling to Japan once a year to speak at the Future of Asia Conference - now into its 19th year, organised by the Japanese media corporation, Nihon Keizai Shimbun (Nikkei).
For a time, I was going to China nearly once a year, although I am reluctant to go to Beijing now because of the pollution. But the leaders are there, so you have to go there to meet them.
The JP Morgan International Council, which I am on, did me the honour of holding its 2012 annual meeting in Singapore, so did the Total Advisory Board.
Going to France is all right. It is a 12-hour direct flight on an Airbus 380, there and back. But to go to New York is much more tiring - especially because of the time change, from night into day and day into night.
Travelling overseas helps me widen my horizons. I see how other countries are developing. No country or city stays static. I have seen London and Paris change, over and over again.
Being out of Government means I am less well-informed of what is going on and the pressures for change. I therefore go by the decisions of the ministers, by and large. I seldom express a contrary opinion - at least, much less than when I was in Government and attended Cabinet meetings, which allowed me to participate fully in the debates.
Occasionally, when I disagree strongly with something, I make my views known to the Prime Minister. There was an instance of this when the Government was looking to reintroduce Chinese dialect programmes on free-to-air channels.
A suggestion was made: "Mandarin is well-established among the population now. Let us go back to dialects so the old can enjoy dramas."
I objected, pointing out that I had, as prime minister, paid a heavy price getting the dialect programmes suppressed and encouraging people to speak Mandarin. So why backtrack?
I had antagonised an entire generation of Chinese, who found their favourite dialect programmes cut off. There was one very good narrator of stories called Lee Dai Sor on Rediffusion, and we just switched off his show.
Why should I allow Cantonese or Hokkien to infect the next generation? If you bring it back, you will find portions of the older generation beginning to speak in dialects to their children and grandchildren. It will creep back, slowly but surely...
Life is better than death. But death comes eventually to everyone. It is something which many in their prime may prefer not to think about. But at 89, I see no point in avoiding the question.
What concerns me is: How do I go? Will the end come swiftly, with a stroke in one of the coronary arteries? Or will it be a stroke in the mind that lays me out in bed for months, semicomatose?
Of the two, I prefer the quick one.
Some time back, I had an Advance Medical Directive (AMD) done which says that if I have to be fed by a tube, and it is unlikely that I would ever be able to recover and walk about, my doctors are to remove the tube and allow me to make a quick exit. I had it signed by a lawyer friend and a doctor...
If you do not sign one, they do everything possible to prevent the inevitable.
I have seen this in so many cases... Quite often, the doctors and relatives of the patient believe they should keep life going. I do not agree. There is an end to everything and I want mine to come as quickly and painlessly as possible, not with me incapacitated, half in coma in bed and with a tube going into my nostrils and down to my stomach.
In such cases, one is little more than a body.
I am not given to making sense out of life - or coming up with some grand narrative on it - other than to measure it by what you think you want to do in life. As for me, I have done what I had wanted to, to the best of my ability. I am satisfied...
Different societies have different philosophical explanations for life and the hereafter.
If you go to America, you will find fervent Christians, especially in the conservative Bible Belt covering much of the country's south.
In China, despite decades of Maoist and Marxist indoctrination, ancestral worship and other traditional Buddhist or Taoist-based religious practices are commonplace.
In India, belief in reincarnation is widespread.
I wouldn't call myself an atheist. I neither deny nor accept that there is a God. The universe, they say, came out of the Big Bang.
But human beings on this earth have developed over the last 20,000 years into thinking beings, and are able to see beyond themselves and think about themselves. Is that a result of Darwinian evolution? Or is it God? I do not know.
So I do not laugh at people who believe in God. But I do not necessarily believe in God - nor deny that there could be one.