I have a confession to make – I firmly believe that self-service checkouts are the devil's work. Having attempted to use them many times, I have always, without fail, ended up in a blind rage, frantically waving some item or other around under the scanner while a robotic voice shrieks "problem in the bagging area".
Unless you have one item with an enormous barcode, don't bother going to the self-service checkout, because I can assure you, no good will come of it and you'll end up with extremely high blood pressure.
Not only will you be personally frustrated, but you will also have a long line of people behind you, rolling their eyes and huffing as you try to reason with a metal box.
The good news is, I am not alone. According to a UK-wide survey, one in three customers has walked out of a store because of a bad experience with a self-service till.
The irony is that these machines are supposed to make life easier for us. They were installed in almost all major shops amid claims that they were faster, more efficient and more convenient.
And yet 84% of people surveyed admitted to needing staff assistance when using the checkouts, which kind of defeats the purpose. They do not make us autonomous shoppers, they make us needy and furious.
More than half the people surveyed believed that it took longer to get through a self-service checkout than a normal one. Surely, if so many people need assistance from an actual human being, then the claim of it being self-service is null and void?
Being exceedingly irritating is not the self-service checkouts' only flaw. Apparently they are also turning us into shoplifters.
A report carried out by www.VoucherCodesPro.co.uk found that one-in-five customers using self-service checkouts admitted to stealing, resulting in a cost to shops in the UK of more than £1.6bn a year.
Of those who admitted to stealing, more than half said it was because they got so fed up trying to scan items that wouldn't register. Anyone who has ever tried scanning fruit and vegetables at these checkouts will understand this frustration.
But it's not just the odd carrot that's being thrown into the bag unpaid for. The problem is escalating at an alarming rate.
George Charles, spokesman for www.VoucherCodesPro.co.uk, says: "I'm sure most of those who now admit to stealing via self-service checkouts didn't initially set out to do so – they may have forgotten to scan something and then realised how easy it could be to take items without scanning them."
The problem is, once people steal and get away with it, it can become a habit. Thus Charles recommends that supermarkets increase the number of staff monitoring the checkouts. Once again, this defeats the whole goal of self-service.
Customers in the US have got so fed up that many of the big stores are now phasing out self-service checkouts and putting in more staffed checkout aisles. I for one am hoping the same will happen here.
My other bugbear with self-service checkouts is they take away from conversation. Old-age pensioners can often be very lonely. A cheery smile and a chat with a checkout assistant can raise their spirits. How could we take that away from them?
On a positive note, worries about self-service checkouts taking away jobs hasn't materialised. With almost everyone still needing assistance at some point, the machines haven't cut many jobs.
And with more security needed to stop the frustrated shoppers from stealing, it appears the self-service machines may actually be increasing employment.
My advice is to stick to the old-fashioned checkout aisles, where humans speak to you and, sometimes, even smile at you. No machine can provide that service.