In pretty much every episode of the Lone Ranger, there was a point, usually just after the William Tell overture, w the baddies got away, and the trail went cold. And so did the show. Then mysteriously, after a day or two of uncomfortably introspective faffing about in the desert, the dynamic duo would stumble across hoof prints. Tonto would put his head to the ground and listen.

“Three horses -- maybe two days ago -- and lame donkey -- heavy prints -- many guns -- lead north” he said.
“By Jiminy - they're headed to Devil's Creek” said the Lone Ranger “We'll cut them off at Cactus Gulch”
“More” said Tonto “man on lead horse called Frank Cartwright. Him lose much money today to Indian scout “
The Lone Ranger is gobsmacked “How can you know that Tonto?”
Tonto held up the evidence “Him drop credit card. Shopping, Kemo Sabe?”

Okay I made up the last bit. But as a kid, Tonto’s deductive skills impressed me no end. How could he be so sure that they were on the trail of Mexican bandits? How did he get it right all the time? Or were there dozens of episodes we were never allowed to see where Tonto completely screwed up. And the Lone Ranger ambushed a Women's Institute picnic instead of the high Sierra hideout of the notorious Hole in the Carpet Gang. Tonto would put his head in his hands. “Tonto get coat, Kemo Sabe”.

I think I would have made a good Indian scout. I've been applying these same skills while shopping in the local supermarket. Before you say anything, I don't get dressed up as a Potawatomi brave to do my shopping. Well, not every week. Nor do I lie in the car park smelling tyre tracks “1998 BMW 3 series, two kids and a Rottweiler called Fang. Stuck in M25 contraflow. Near Cactus Gulch”.

No, forget the car park, I’m talking about the contents of shopping baskets. I'm not a nosy person but I can't help looking at other people’s shopping whilst affecting an air of nonchalance. If I'm waiting in the queue at the supermarket, there's precious little else to do -- it's what computer people call ‘downtime’. With PD, I am aware that, in the future, I will be spoilt for downtime, so I try to use each moment of ‘uptime’ to some useful purpose. Besides, the contents of the trolley or basket read like haikus -- slices of people's lives. Who needs ink blots when you can extract a detailed psychological profile from what people put in their shopping baskets.

I’ll give you an example: small white loaf, a pack of rich tea biscuits and two tins of deluxe cat food. Is the owner (a) Ottavio, a 28-year old Italian graphic designer who has just launched his own dotcom that afternoon, or (b) a 79-year old widow called Mabel whose best friend Smudge is ‘such a fussy eater’?

OK, that was an easy one. You all got Ottavio, right?

Want to try another – Four pack of Carling, Babycham, family size bag of Doritos, pack of condoms and a tube of Clearasil? What can we say of him?

Is he (a) Charles, a suave, urbane stockbroker with a yacht moored in the bay or (b) Carl, a spotty teenage optimist whose evening is definitely not going to pan out the way he thinks. Pound to a penny his teddy bear will be the only thing he snuggles up to tonight. . 

There you go – you’re getting the hang of this. Before you know it, you've turned into Cracker or Hercule Poirot without the daft ‘tache. At least it helps while away the hours spent either shopping or queueing to pay. And you'd be amazed how many hours that can be.

Calculators ready?

I am 53. I am a big boy now and have been doing my own shopping for the last 35 years. Despite this, Claire despatches me to Tesco with a lengthy list containing instruction more detailed than the tempo markings on a Mahler symphony. Often she will talk me through it in advance ‘Passion fruit fat-free low sugar yogurt from managed Brazilian rainforest – they’re on the shelf beside the cholesterol-lowing ones but with a different colour lid. Only buy if the 2 for 1 offer is still on. Otherwise buy the mango and guava fruit corners on the next shelf under the kiwi and banana milkshakes.” Being a man I hear the word “yogurt”. And nothing else. I make a mental note – ‘buy some yogurt’.

When the shopping list runs to 2 pages of micrographic writing, I know I'm in trouble and try to recruit help. Alice never comes – I am far too unfashionable to be seen with her. And Alex would rather do homework. Shopping with dad is that enticing. If Catherine comes with me, we speed-shop. And we improvise. Claire always interrogates us on return with the same question “Did you get every item on the list?” and I’ve learnt that cheery responses like “Quite a few of them” and “Well over half” do not afford Claire the level of reassurance she is seeking. It’s a cry for help.

But I digress – back to the shopping. On average the weekly shop takes say 60 minutes. Actually it's probably longer now I think about it but we'll stick with 60. Of that 60 minutes, perhaps 10 are spent in the queue at the tills. Thus far I have spent 303 hours standing in a queue to pay. That’s 303 hours of downtime. The equivalent of 10 test matches. Five premiership football seasons. The combined flight time of the entire Apollo moon landing program. Some insect species evolve in less time than i have spent queueing. If you add the hours spent wandering like a zombie up and down the aisles, it amounts to more time than I spent in lectures as an undergrad. And I did a four-year course.

All in all, I have spent -- get this -- the waking hours of three entire months of my life in a supermarket. And nearly two weeks alone standing at the till pretending to be Tonto. I bet Tonto never struggled to open the carrier bags. He would have gestured to Tiffany on the till “Squaw’s work”. Nor, I imagine, would he shakily spill his change on the ground, and watch in misery as nearby children helped themselves to the larger denomination coins. Apparently the supermarket is an extension of the playground and the rules of “Finders keepers” still hold sway here. It's not every day you spend £9.33 on a Crunchie. I shall watch out for the Locust children next time.

I suppose I shouldn't complain. The other day I read that an ordinary loaf of bread cost nearly a million pounds in Zimbabwe. I phoned Charlie.

“Amazing” he said “I didn't know they had Waitrose over there”.