As my mother likes to say, life’s a shit and then you die. Not only that, but many of the things that help mitigate the shit – overeating, drugs, booze, brain-addling TV, tobacco – are likely to make you die sooner rather than later. So the clear-eyed choice is between eking out an existence of miserable and abstemious longevity, and one where the booze, as well as getting you pissed in the short term, bestows the added boon of an early grave.

Most of my youth – even the pre-alcohol phase – is now recollected through a glass darkly, the obscurity disseminated by a pall of tobacco smoke. Nearly everyone, including my parents and all their friends, smoked, and smoked voraciously. Apart from the Saturday matinée, cinema visits used to resemble an Iron Maiden concert. James Bond, Mary Poppins and the rest were dimly glimpsed through a haze of carcinogens. My grandmother got through sixty Benson and Hedges a day, well into her wheezing dotage.

This week the Commons debated the clause in the Children and Families Bill that outlaws lighting up in any private vehicle that’s carrying children. MPs voted by well over three to one (376-107) for the ban, on the presumable basis that as only about one-fifth of UK adults smoke, the electoral gains outweigh the risks.

It’s all as depressing as health food and follows hard on the heels of the UK smoking ban of 2007; last year Strasbourg followed up by banning menthol gaspers. In Britain, wretched smokers are now banished from bars and eateries to pavements in the drizzle to indulge in their entirely legal drug of choice, denied even the fume-boxes offered by Belgian clubs. The sane solution – to create two categories of licence for bars, restaurants and so on, so that customers could choose whether or not to patronise a smoking establishment – passed MPs by when the smoking ban came in; the state could, if it wanted, make smoking licenses dearer to flag up its disapproval of the habit.

In Germany – seldom noted, at least in the UK, for its jealous guardianship of civil liberties – the ban, where it exists at all, is widely and wisely flouted. In Berlin over Xmas I used to visit the smoking bar up the road from my flat in Prenzlauer Berg, even though I don’t really smoke any more, just for the retroish thrill of inhaling nicotine-rich carcinogens again in a pub. Objectors divide between people who say there’d be no market for smokers’ bars – in which case there’s nothing to worry about – and those who argue there’d be too much of a market, in which case a ban seems not just paternalistic, but oppressive. Certainly the law should safeguard the health of bar and restaurant workers, as proponents of the 2007 ban argued, but demand for smoking bars broadly fluctuates in step with the habit's incidence in the population at large, and the sector has a high level of occupational mobility.

As usual with nanny laws, no account is taken of the opportunity costs incurred in policing it. Children, especially young ones, generally have a low profile in motor vehicles. Will snatch-squads of roadside plods lie in wait to flag down any motorist seen puffing on the off-chance that there may be a toddler strapped into the back seat? Will the ban extend to smokeless e-fags? Will pregnant women who smoke behind the wheel get whacked (and how long will it be before expectant mothers are banned from smoking whether or not they’re driving)? What about dachshunds that find themselves holed up in a Mini Cooper with a clutch of chain smokers?

Here’s the bad news, from my mother. We’re all going to die. Why spoil the fun for kids who want to smoke in their parents’ car?