OLD people are at it.

I came to this conclusion on perusal of my mother's hair.

Ma Stewart is of a certain age, an age at which I would guess my grandmother had already been in possession of a blue rinsed perm for at least 10 years. Perhaps 15. Ma Stewart, it occurred to me, has the hair of a young woman, despite, technically, being elderly.

Thinking more, it occurred further that I'm not sure I know any old or elderly people. I know people who have achieved a hearty number of years, certainly, but would I call them old? Not to their faces.

My lovely uncle Tom (70) runs, swims, cycles (triathlon, do they call it?) and has lately taken up an interest in being a television extra, leading him to a speaking part on Outlander. Elderly? No one's fooled.

Ditto my aunt Margaret (and here I demure in case of offence. Sexist? Yes, but also sensible) who has passed retiral age yet has pins to rival a young Angela Rippon (now 70 and still athletic).

My friend's dad Angus is in his 80s (she's 31) and you've never seen anyone cut up a dance floor the way that man cuts up a dance floor. Sprightly, you might say, if sprightly wasn't such a patronising term for older people.

Lynne Berry, chair of the Commission on the Voluntary Sector & Ageing, launched the commission's final report last week, saying charities should stop using pictures of "half-dead Ethel" to promote their services.

Old age has changed so much in just one generation - but public perceptions of the elderly have not. Elderly is slippers, cardigans, gnarled hands knotted fretfully together, surgical tights and knee high socks under crease fronted brown trousers.

That is, elderly in the press or elderly on those leaflets asking for donations to old age charities. Yet, Gold Age Pensioners, a report commissioned by the Royal Voluntary Service, showed the elderly (over 65s) made a net contribution of £40billion to the UK economy in 2010, expected to rise to £77bn by 2030. The report also estimated the value of older people's volunteering reaches £10bn per year.

It that the silver pound? Or is it just people who happen to be in a similar age bracket spending money?

You see many images of half-dead Ethel in print when anything old age-related is publicised. Why isn't Helen Mirren (69) the go-to stock image for the elderly? Or Joan Collins (81)? If I was in my elderly years I'd be affronted at the default depiction of me wrinkling behind net curtains with a zimmerframe next to my under stuffed, brown arm chair.

Sir Muir Gray, NHS ex-chief of knowledge, has been telling old people to chuck the slippers and start moving more, speaking both at the Oxford Literary Festival this week and in newspaper opinion pieces.

I wonder who he means? The old people of my acquaintance are too busy chasing grandchildren to have time to leisurely slipper wearing.

I've tried to find out how old "elderly" actually is. "Rather old," according to Merriam-Webster, unhelpfully.

Simone de Beauvoir said we see old age as "something alien, a foreign species". I wonder what old age will be like by the time I'm privileged enough to experience it? Will grey hair and sturdy lace ups become a thing of thing of history as 80 becomes the new 55?

The elderly go to tea dances. I can't imagine any of the soi disant elderly in my life having time for tea, let alone tea dances. Nor the inclination. Will tea dances be a figment of the past by the time I'm old enough to attend them?

When I was really young, the elderly seemed like a foreign species. Now they seem just like us.