44 days, 35

In the queue at the supermarket. The woman in front seems airy and distracted: she spends five minutes staring into her wallet and moving little papers about (sounds a bit like me, doesn't it?); she's got one of those high, shallow shopping trolleys, with a basket up high and a storing rack underneath. In this, I notice, she's got her coat and a box of detergent.

Eventually she starts loading her shopping onto the rolling check-out thingie. 'She'll forget the detergent', I think. She forgets the detergent.

Ummm-huh. This – I realise now – is one of those situations that happen to someone else, but say a lot about me. There's this choice I suddenly have to make: do I get involved? Do I look the other way? I wish she'd dropped something and carried on walking; then I'd know what to do.

I wonder, briefly: did she forget the detergent? Is she trying to pass it through unnoticed? Do I tap her on the shoulder? At this point, it will attract the attention of the shop assistant, and embarrass the woman even more. Also, if she's actually stealing the stuff, it'll piss her off considerably. All awkward and very unpleasant.

Now her stuff is going through and I still haven't made up my mind. She's paying. I look around: huge supermarket, the light, the noise, the masses. Once I saw someone drop a whole box of wine after buying it. It smashed on the floor and ruby liquid pooled around shoppers' feet until it looked like a fresh crime scene. They brought out a new box of wine without a blink and the guy went home happy.

I'm not going to say anything. I've decided. There's a chance she's simply forgotten about it, in which case she'll have a nice surprise. Either way, the supermarket won't even notice (OK, the literal thought is 'stuff them'!)

She's wheeling the trolley away. My turn. No, wait. She stops, turns. 'Oh, she says, I almost forgot.' She pulls the detergent out. 'I was robbing you without meaning to...' The detergent – 8.99 – is passed through and she pays. She pays in coins of 5, 2 and 1 cent only. It takes a decade.

I'm starting to wish she'd walked away with the damn thing.