Hats off to Heather McCartney. Yes, I know that she is chillingly, pointlessly mad, but I can’t help feeling that she is doing our nation some service.

So when I rang to cadge some pro-Heather quote off a friend who knows her, explaining that I was experiencing some mild but not unduly alarming feelings of warmth towards the woman and was considering writing something nice – or at any rate not too horrible – about her, it didn’t go well.

“As the imbecile who introduced Sir Paul to Heather Mills, I can only offer my sincere and heartfelt apologies to him,” said Piers Morgan, former editor of the Daily Mirror. “The only positive aspect of Heather’s hilariously absurd behaviour is that it will now be bleedingly obvious to everyone why he left her.”

So I know I am swimming against the tide here. But I find I can’t call her “Mucca”. I don’t feel up to calling another woman a slapper name used to evoke her dodgy topless past rather than her marriage to Paul “Macca” McCartney. And although I think that it’s foul to air your dirty linen in public on national television on both sides of the Atlantic and to blackmail a national treasure – not to mention the composer of Mull of Kintyre – as she has, I can’t join in the public stoning of this damaged, delusional, narcissistic, walking wounded one-legged blonde, because that’s even sicker than she is.

For although she may well be a gold-plated liar and gold-digger, none of which is any of my business, she is also brave. Totally crackers, of course, but ridiculously brave. She’s a disabled single female who also has the handicap of being blonde and attractive (which means that women will hate her on sight and men will respond to her in some primitive psychosexual way, I am told) and she has taken on not one but two powerful establishments.

First, by marrying a Beatle she has taken on all the millions of baby boomers for whom the band meant everything and for whom Paul remains the living, breathing incarnation of their adolescent hopes and dreams.

Second, she has taken on the British press with attacking interviews both here and in the United States, undertaken in the hope presumably of scaring Paul into coughing up but ostensibly to promote her latest campaign, which is to protect the victims of the press. How she can succeed where our libel and privacy laws fail I don’t quite see but, in any event, I do think that our tabloid newspapers have gained the opponent they deserve.

Mills will lose against both McCartney and the media, it goes without saying. Still, the madder a woman is, the more dangerous, and she is casting herself as a vengeful suicide bomber prepared to kill herself in order to take down others. “I’ve nothing left to lose,” as she herself pointed out. That would scare the pants off me if I were Paul – which, phew, I’m not.

Anyway, I still felt sorry for her and a bit shocked by the herd instinct in the raddled army of mean cows who were wheeled on to exterminate a woman whose only real mistake was to marry Paul McCartney. Not since Yoko Ono, not since Posh, has someone been held in such opprobrium for being, as one writer put it, “the wrong woman to marry the right man”.

So let’s, for a change, look at all the positive things that she has achieved, beyond her charity work that we hear so much about. And they are not inconsiderable. One, she has made every man who cannot match Paul for fame and talent feel that he may not have done much with his life but at least he never married Heather and, in that sense, he’s luckier than a Beatle.

Two, Heather’s bonkers behaviour has, in contrast, made the comportment of almost every other woman in Britain look a model of seemliness, to the extent that we should be deeply grateful that she is making us look so good, rather than lining up to trash her.

Three, she has made every gloomily married man and married woman on both sides of the Atlantic feel rosier about their own marriages in the wake of the Vesuvian eruptions of the public and bitter McCartney divorce.

In fact, so far as I can make out, Heather Mills has done more to unite the English-speaking peoples than perhaps anyone since Hitler.

Notting Hill has rightly annoyed many for being too pleased with itself, too expensive, too chi-chi. But on Hallowe’en night, marauding hordes from other postcodes still descend on this part of west London and go about the stuccoed streets that enclose secret communal gardens and the houses painted in ice-cream colours.

I stood on my own weed-infested doorstep and saw the streets swarming with witches, fairies, goblins and, as the evening wore on, shrieking teens in fright wigs and ghoul masks.

The neighbourhood was transformed into a Harry Potter movie. A couple of £7m mansions nearby were converted into haunted houses and the investment bankers changed out of their suits to become walking zombies or Draculas and seemed cheerful for the first time in ages.

Up the road in W10, Rik Mayall was giving street performances outside his house and, according to my tiny spies, David Cameron seemed confused to find a gaggle of costumed trick or treaters on his doorstep expecting sweets. “Can I help you?” he asked, seemingly unaware of the tradition. “Sorry, it’s bathtime,” he said and closed the door as his daughter was heard accusing him of being “boring”.

My supply of sweets ran out so fast that I had to stick a sign on the door apologising in case things got nasty. As I did so, I briefly considered placing my own lit pumpkin on my next door neighbour’s steps, as a trick to divert traffic from my house to theirs. I resisted the temptation – I knew my architect neighbour was skulking it out with his designer wife in a darkened basement – but regretted it as a fresh crew of Harry Potter extras with pram-pushing, gum-chewing mothers mobbed me on my own doorstep. As I distributed cupcakes from M&S, which were all I had left, I had a sudden flash of what our Queen might feel as she doles out Maundy money.

My own children are far too big to be dressed as pumpkins (and I do think there should be an age limit of about eight when it comes to the festivity, which is second only to Christmas as a spending opportunity) but Hallowe’en did seem slightly less awful this year and the egg-throwing hoodies stayed away.

In my neighbourhood, it has become not so much a pagan festival but an annual act of social reconciliation between the haves and the have-nots, a bridge between Notting Hill and Shepherd’s Bush, and an acknowledgment that – strictly one day a year – it’s good for the privileged rich to open their front doors and offer a fun-size Twix to the sort of people they never usually meet.

rachel.johnson@sunday-times.co.uk

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