I’M ABOUT to join Madonna, Michael Jackson, Barbie and Paddington Bear.

In case you didn’t spot the connection, they’ve all recently turned 50, and I’m now planning my 50th birthday party, with some trepidation.

It’s not that I mind being 50. When I compare myself with my famous contemporaries, I can’t help thinking that I’m not doing too badly.

Paddington and I are handling the ageing process gracefully: a little hairier, a little greyer, but without the use of plastics, whiteners or any other surgical procedures. Mentally, neither of us were exactly sharp to start with, so it’s hard to know what’s senility and what’s just our normal day-to-day confusion. But I’m starting to think that keeping sandwiches under my hat, always carrying a packed suitcase and hanging a label around my neck are rather sensible precautions against early onset dementia.

Madonna’s doing her Peter Pan thing and is still looking and sounding great. I’ve always admired her ability to adapt and reinvent herself.

But I wouldn’t want to be in her shoes right now. She may be taking the whole Madonna and child thing too far: what with the bit-too-young-not-to-be-creepy 22-year-old lover, and her quest to adopt a daughter in Malawi.

Instead of battling so hard against nature, I’d like to see Madonna becoming a new kind of role model for our generation of women by relaxing into middle age with something approaching wisdom. I know Madonna purposely uses her ability to shock as a way to challenge prejudices, and that’s what she may be doing right now: why can’t women go on being parents (like men do), even after their biological clocks stop ticking? And why can’t older women take beautiful young lovers (like men do)?

I get all that. But rather than being shocking, this time I’m worried she’s just fallen into the biggest stereotype of all and she’s having just another, boring, post-divorce, mid-life crisis (like men do).

I’d much rather she’d use her talent for reinvention by accepting nature’s own changing process and going with the flow of this mid-life, menopausal stage. Take it from me, it’s not such a big deal.

As for Barbie, she’s been the one woman of my generation who has genuinely broken the glass ceiling and had it all: babies, careers, the Presidency and Ken. Obviously, when it comes to the issue of plastic, Barbie had a head start. And unlike Jacko, whose surgical procedures had horrifying consequences, Barbie will forever escape the laws of cause and effect and gravity.

Barbie’s impressive FF cup size boobs remain just as pert and perky as they were in 1959. In reality we all know that a woman shaped like Barbie would be 7ft 2in tall and have to crawl on all fours because of her enormous chest and tiny feet (someone’s also worked out that she’d only have half a liver and four inches of intestine because of her ridiculously small waist).

So, as I was saying earlier, my trepidation is not about wrinkles and decay. It’s just I rashly announced I was going to have a party, and now realise I ought to be doing more about it than vaguely mentioning it in passing whenever I bump into someone I know.

So far I think I’ve done that to about 200 people and I can’t decide whether that’s a recipe for an incredibly good party or a total ‘party from hell’ disaster.

I’m trying to be outwardly all ‘Zen and the Art of Party Planning’. That worked brilliantly last year when I didn’t do anything at all and ended up having one of my best birthdays ever.

Part of my problem is that I gave birth to my youngest child on my birthday and so the last eight years have been great. There are not many adults who can legitimately lay on egg sandwiches, marshmallows, things on sticks and jammie dodgers every year throughout their 40s.

Last year I took a bunch of little boys to play Quasar Laser and I got told off for taking it too seriously and scaring children when I jumped them from above, screaming, with my face blacked like Rambo.

It wouldn’t have been so bad, but my son’s best friend had a bad neck, so they both sat outside quietly discussing the meaning of life while I ran around terrorising the rest of his school friends. It was the best fun I’d had in years.

In the evening I’d planned to meet a couple of friends for a sophisticated, early evening cocktail or two, and then home early to bed.

In fact, loads of people turned up. I was still hyper from playing Rambo and the e-numbers in the children’s party food. Plus I discovered a passion for Long Island Iced Tea. Do you know there’s no tea at all in those things?

It was fun and I was asleep by 10, though sadly I was still in the cocktail bar and not at home in bed.

But back to this year. Inwardly, the idea of being in charge of a proper grown-up party terrifies me.

Does that mean I have to sit down and start writing lists?

Also (seeing as I’m nearly 50 and approaching senility), I don’t know who I’ve invited and who I’ve forgotten.

I know this is going to seem incredibly lazy and disorganised but who cares, (lazy and disorganised are recurring themes in my life, alongside ‘bad mother’ and ‘nutty veggie woman’).

So here goes: This is an official invite to anybody who knows me, who I’ve not seen in the last couple of months — Party, My house, Next Saturday.

Sorted.

My daughter and I have just had a discussion about whether my party is in fact next Saturday or the Saturday after next.

In my view this Saturday is this Saturday and next Saturday is next Saturday and it’s clear. But there are people who say next Saturday when they mean this Saturday. So just to be sure nobody turns up on the wrong day, my party is not this this Saturday. It’s definitely next next Saturday. And it’s not the Saturday after next.

Now I think all I have to do is blow up the balloons, wrap a pass the parcel with 200-plus layers and get a fire extinguisher for all those candles. See you there (or should that be here?).