Years and years and years ago, in another lifetime, I overheard a mother reasoning with her toddler.

‘Honey, you need to understand that what you just did has made mummy very sad.’

I remember stopping dead in my tracks and staring at her wondering what planet she’d come from. The kid was three, maybe four. All he needed to understand, he understood. Scream loud enough and mummy will or won’t give me what I want. 50/50 chance. Play the odds.

Toddlers are not teens I know. Yet a couple of times this week, I found myself reasoning (or trying to reason) with the boy. And I wondered why. It’s not like I was ever reasoned with. I turned out just fine, thank you very much, on a diet of ‘ ‘because I said so’ and ‘do as your told’. Back in the day, adults trumped children – children of any age.

Yesterday, we had intended to go to the Natural History Museum but it got a short shrift when we spotted the LEGO shop at Allee. We’d gone there to see if the Samsung shop had a cover for my phone and the plan was simple. Five minutes in Samsung, then back to Bubba’s for fish and chips, then to the museum. All planned out, agreed, and more importantly, accepted.

But I broke the rules. I cheated. I went into Von Graf to take the in-store escalator up to the next floor and while I was passing the sale rack, I stopped to check if a coat I’ve had my eye on has reached the half-price mark yet. You’d think I’d pitched tent and was hunkering in for the afternoon.

‘Mary – I don’t do shopping. I hate this. We have a plan. We need to go. Now.’

‘Two minutes’, says I. ‘You can wait two minutes.’

We struck out at Samsung and then spotted the LEGO shop. An hour later I was still sitting there, watching, as every box was examined in detail. It was like some sort of religious ritual. He did three tours of the shelves and then came to calculate how much money he had left. But the decision was too serious to take without sustenance. He needed a raspberry chocolate shake from Costa before he made up his mind. I’m useless in the face of such specificity.

Duly fortified, back we went. And it took another hour. I kid you not. Even I’m not that indescisive, I thought. But no – it wasn’t indecision. He was going through some abstract exercise, weighing up the plusses and minuses of each decision, including projections involving future collections. This wasn’t a short-term deal. We’re talking about choosing next year’s LEGO path. He obviously got all the vision genes.

Decision made, money handed over. Next stop food and an insight into what he’s like.

‘Mary, I’m the type of person who has to do something – now. I have to go home and put this LEGO piece together. If I don’t do it now, I won’t be able to think about anything else.’ Well, fair enough. Nothing like knowing what makes you tick. And I’m no stranger to that sort of single-minded obsession.

So home we went.

Later that evening, as we looked appreciatively at a model of the UN Building in New York, I mentioned going to another mall, to another Samsung shop. To see if they had my phone cover. I, too, had wants.

But it took some persuasion. And I found myself playing the ‘not-fair’ card. I waited two hours in a LEGO shop for you, and you won’t even give me half an hour to come with me to get my phone cover? What’s that about?’ And I wondered, not for the first time this past week, which one of us is the adult?

I’ve come to this way too late in life. I don’t have the inner fortitude to trot out a few ‘because I said so’ or ‘do as you’re told’. Perhaps if it was a full-time, long-term gig, I’d be different. But hey – he’s on holidays.