I trust you didn't spend yesterday with a divorce lawyer. Thousands apparently did, since it was trumpeted as Manic Monday when everyone resolves to change their life. Most do it with resolutions, diets, job applications and holiday brochures. Divorce lawyers, however, brag of a “deluge” of calls on this baneful day. Research claiming that matrimonial firms are twice as busy in January emanates from their chirpy website entitled insidedivorce.com, whose subtitle - yeuch! - is “Winning the life you want”.

Which should act as a warning, if fed-up spouses would only notice it before scrolling down the chirpy checklists on how to find a lawyer, sell the house, book a child psychiatrist and fix a prenup contract before you remarry. That subtitle, frankly, contained every warning you should need. “Winning” is a happy word for lawyers but not an appropriate one for divorce. Divorce is sometimes necessary but always lousy. Nobody wins. It is a public admission of failure - either you made a stupid decision when you got married, or else one or both of you has deteriorated into a nastier person.

As for “the life you want”, come off it. The path to happiness after divorce is not as smooth as sloganeering lawyers might want you to think. Easier, perhaps, after a brief and childless “starter marriage”: some young couples stay friends and stay cheerful. But even they must find a way to swallow the ignominy and waste of having spent tens of thousands on a wedding and solicited expensive presents, only to fall apart like a duff sponge cake.

Most divorces, though, happen over 40 and after more than a decade; more than half involve children under 16. Don't do it. Or if you must (and occasionally it is true that the alternative is cruel misery) then try not to decide in January. Not when you're broke and bloated and hungover and traumatised by prolonged contact with certain in-laws whom you fear your spouse is growing to resemble. You may just be living the immortal song by the spoof country legend Tina C: “Every day with you is like Christmas - I feel fat and bored.” At least let the daffodils come up before flinging yourself into the octopus embrace of the law. You might survive divorce - we all know happy second marriages and single lives - but it is never fun. Never.

Do 406 British marriages a day really need to end? Or are we becoming divorce-addicts, dashing for the adrenalin rush of change? Only a third of petitioners claim abuse (and that includes “emotional abuse”, an expression subject to all sorts of hysterical me-generation overstatement). Forty-two per cent cite infidelity - though the figures do not distinguish between a silly one-night stand and prolonged disloyalty - and the rest claim “boredom” or insufficient sex. But life is often boring and sex scanty. Things can be improved by other means.

Don't crack a nut with a sledgehammer. So perhaps a hobby for this perilous week is to list the reasons not to do it, or not yet.

First, your judgment may be impaired by marzipan, booze and Visa bills. Any general yearning for change will naturally focus on the pallid, grumbling, sneezing lump in the corner. But he or she is unlikely to be the only problem. Admit it.

Secondly, think of the financial upheaval. You will probably have to sell the house, on a falling market (the lawyerly website is full of vapid old-hat advice about “decluttering” and baking bread). You will not only be introducing lawyers into your life, but estate agents too. The horror, the horror. Better to move into the shed with a Lilo for a month or so, while you think.

Thirdly, far more importantly, if you have children they too will pay the price. You can limit the damage, but that will involve intelligent effort over a long period. Unless the spouse being discarded is really evil, the children will get sad. Dealing with that sadness, and refraining from making it worse by using them as pawns, will be hard work. It may actually involve more determined love, patience and understanding than you could have spent in sorting out the marriage in the first place.

Fourthly, there are only two ways to divorce: well and badly. If you do it badly, in a quarrelsome and petulant manner, it will be vile - not only for the children but for you. There will be a reservoir of venom and resentment in your head for years. It will make you less pleasant to know, and drive away all but your most placid friends.

On the other hand, doing divorce well - and I know several shining examples of this - will involve at least one partner behaving in a saintly manner, heroically refusing to take offence, accepting financial and emotional unfairness, living closer to the ex-spouse than is comfortable, and often setting aside personal fulfilment and new relationships in order to keep the peace. It is exhausting. I honour those who manage it. But some, after a drink or two, tend to admit that it might have been better to work things out, or forgive the affair or whatever.

So don't be conned by lawyers, or by celebrity mags full of airbrushed tales of how divorce “really made me grow”. Don't buy the idea that a decree absolute is equivalent to “winning the life you want”. Borrow Churchill's motto, which he discreetly abbreviated to KBO: Keep Buggering On. And in case you think I write from some hearts'n'flowers idyll, know that I have just asked my husband of 28 years what he would say to dissuade people from January divorces .

He replied gloomily from behind the paper: “Tell them it's not worth it, they'll only get remarried and have it all to go through again.” Happy New Year. KBO.

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