LIFE begins at 40. What's more, it gets even better at 50. So why haven't advertisers cottoned on? For a start, the majority of new cars are bought by the over-50s - including most swish and sporty convertibles. But advertisers seem to think that as soon as you hit the big 50 you go straight from sex, drugs and rock and roll to the joys of the Stannah stair lift.

Try telling that to the Calendar Girls.

The under-30s are divided up into ever narrower bands that gladden an adman's money-making heart - babies, toddlers, tweenies, teenagers, students, yuppies, dinkies and any of the other strange acronymic names. Every month they seem to devise a new market to aim for.

But hit 50 and you suddenly all get lumped into one grey and boring mass - Joanna Lumley in the same bracket as Thora Hird; Mick Jagger with Sir Edward Heath.

Now, at last, a new report by the Millennium Research Bureau is challenging advertisers to think again. And they've divided the grown-ups into much narrower bands, long after the traditional ad-land cut-off of 44. (Why 44? Do people stop buying interesting things at the age of 44?)

Anyway, there are the Aspirers - they're the 45 to 50-year-olds. Don't quite know what they're aspiring to - maybe just being 50.

Next come The Thrivers. These are people aged 50-59, whose children are just about educated and who have dwindling mortgages. They're the ones - oh, joy! - who buy the sports cars and the Harley Davisons.

The Seniors are aged 60-69. Still, apparently, mainly with their own teeth, a few brain cells and a distinct sense of adventure. If they've still got some money in the pension pot, they're the ones buzzing all over the world, their only concession to age being that they do it in style and luxury.

And finally there are the Elders (70-plus) and Super Elders (80-plus), but many of them with dramatically different lifestyles than most 80-year-olds ever dreamt of in the past.

And just as the under-30s category keeps expanding, no doubt the over-50s soon will too, as the old stereotypes are finally abandoned in the face of a dramatically different reality.

Personally, I'm looking forward to a bright yellow sports car and seeing some very rude adverts for Club 50/60 holidays.

And a chance, at last, to grow old disgracefully - with or without the stairlift

A SUMPTUOUS house in London - more than 50 times the size of your average semi - has just sold for a world record price of £70m.

The previous owner, Labour supporter Bernie Ecclestone, never actually lived in the house. But he bought it for £50m, and so after three years it has made him £20m, just by sitting there empty.

A cheering thought for the struggling first time buyers to ponder.

MARKS & Spencer are planning a major revamp. Sales of ladieswear have been falling rapidly. They think they've found the reason. They have decided, apparently, that we don't like the look of their green carrier bags. And so at vast expense - conservative estimates say millions, some say as much as an incredible £1bn - they are getting rid of that nasty green and bringing in a nicer darker shade, mixed with pink. Very tasteful.

Well yes, I'm sure the carrier bags will look lovely.

But unless they put as much effort into redesigning their ladieswear as into revamping their stores, it's not going to make much difference. Too many of their clothes are drab and dreary or just downright odd, with precious few interesting basics in between.

If only they put as much pizzazz into their clothes as they do into their sandwiches, then we wouldn't care less what sort of carrier bags we were taking them home in.

TODAY is a momentous day - Smaller Son's 20th birthday, which means I am no longer the parent of a teenager and by any standards, the boys must now be considered to be men and fully-fledged adults.

But I remember some author's biography printed on the blurb of the book jacket. It said that she lived somewhere in the country "with her sort of grown-up sons.""Sort of grown-up"? I think I know exactly what she meant.

SWIMMER Mark Foster just missed out on the time needed to get into Britain's Olympic squad and so hasn't been picked. Is he going back to the pool, resolving to train harder, faster for next time? No. He's in a sulk and is going to sue. This could set a dangerous precedent. How long before disgruntled footballers get the same idea? Come to think about it, one of my sons was most put out when he wasn't selected for the Under 11s.