"Old" is really a culture-specific term. Age can be described under many arena eg chronological age, physiological age, mental age, cognitive age, social age......the ideal is: an ageless society where people are not assessed by their whatever age, and the environment is conducive for the development of potentials of people of different age / abilities.....

From someone who is involved in elderly health, I have 2 messages:

1. The current average life expectancy in HK for those at birth is 78+ for men and 83+ for women. That means for those already over 50, the expected lifespan would be even longer. Worldwide experience has shown that the greatest contribution to the increase in life expectancy in populations have been: improvement in the general standard of living (to achieve basic sanitation, clean water, adequate nutrition, etc which is called "primary
health care" by the World Health Organisation) plus education(United Nations has discovered that the most crucial factor affecting infant mortality rate is literacy of women). The variation in lifespan among individuals is more due to different lifestyle practices eg smoking, exercise, eating habits, etc. rather than fate or genetics. The message is: what we have achieved now is more due to our own (and our forefathers' too)efforts rather than "experts". And, for ourselves and our children, we need to pay attention to all these instead of relying on medical advances

2. The ex- Director General of WHO had pointed out that population ageing is first and foremost a success story for public health policies as well as social and economic development. It is one of humanity's greatest triumph....something to celebrate and not to view with undue pessimism....albeit one of the greatest challenges of humankind too as never in human history had there been so many elders into the age 80s, 90s, 00s,110s....

For more reading, visit the webpages on Elderly Health and Ageing:

http://www.elderly.gov.hk

http://www.who.int/health_topics/ageing/en/

Thanks for the response that has attracted the following reaction:

- agree with you over SW's "seasoning" with time: certainly she has not been idle during all these years!

- no need to be jealous of SW: you reap what you sow. We had many years behind us although they do not show.........

- about walking speed. Why compare when you are not on equal grounds? I'm not talking about age. I'm talking about the unpreparedness. Actually it was a hazardous venture. We always advise people not to take up strenuous exercise suddenly if they have not done so for a long time. Muscle cramp is minor. You never know how fit is your heart....which again is fair play. The centenarian obviously has been keeping his body fit. After being well-prepared, perhaps you'd like to try the 100 km walk in HK which is a big annual event?

- about friends in your 80's. My advice on preparedness for ageing (the principle of You reap what you sow again). Invest in the 4 following areas: $(obvious, but many people under-estimate their lifespan) health(it's never too late to look after your body well) meaningful pursuits(so as not to be "bored to death", especially for people who have only "worked" all their lives and hence have nothing to be occupied with after retirement)
company(you have outlived many already and you may outlive more.....anyway, who can claim to have enough friends?)