A few years ago, I was in Palmerston North to MC an event. I went into town to visit a very good book shop there and was passed by a young mum, hugely pregnant and puffing away on a cigarette.

She was pushing a buggy complete with a toddler who'd been sucking on a bottle which was now empty. He was grizzling a little so she stopped to refill it. And from beneath the pushchair she pulled a jumbo-sized bottle of Coke, refilled his bottle and handed it back to the toddler who gleefully resumed sucking away at it.