How often have you had the infuriating experience of getting into the back of a taxi and giving the driver your destination, only for him to turn around and ask you, "Any idea where that is, love?" The only answer is, of course, "No, that's why I'm in a bloody taxi" and, as a by-the-way, "I'm not your love".
It happened to me only recently. I had to get a child to an exam on Westland Row.
Now, the Royal Irish Academy of Music is a lovely, majestic old building. It has been standing there since 1848, but as it has been years since I've been there, I assumed my taxi driver knew where it was. Not a chance.
Up and down the street he drove, infuriating other drivers, until finally letting us out on the wrong side of the extraordinarily busy road as the exam time loomed. We ended up having to ask passers-by and made it with just minutes to spare, but how difficult should it have been to assume he knew one end of the street from the other?
Well, he wasn't alone. According to just-released figures, 11 out of every 12 taxi driver applicants are failing the basic 'knowledge' exam, which involves nothing more onerous than knowing your way around. An obvious skill for someone who makes a living from driving, but not so, it seems.
Only a measly 8pc pass this vital geography part of the licensing test at the first sitting, although figures are much higher for knowing the rules and regulations of operating a taxi -- including the exorbitant fares to charge, one supposes.
Given that all drivers have until January 2012 to pass the test, we can't hope for a much speedier improvement.
Indeed, at the moment the test is taken by new drivers only because Siptu, which represents 400 taxi drivers, doesn't believe that their members need to sit it.
They are threatening to withdraw services if they are forced, but surely if their assumption is correct, the drivers will pass it in a jiffy and everyone will be happy?
The regulator, Kathleen Doyle, is, so far, putting her foot down on the pedal and driving the change regardless, but really, isn't it the very least that we can expect from a professional taxi driver that he or she knows where they are going?
Dublin isn't a massive city like London and yet taxi drivers there are expected to know every alleyway, road junction and landmark before they are allowed to sit behind the wheel, never mind charge passengers for the pleasure.
Taxis are expensive, but extremely handy for short hops around town, which are the fares drivers like most. But if we're going to be faced with a barrage of questions, making us feel like we ought to do the job for them, we might as well drive after all.
Many taxis are fitted with GPS systems, but they are not infallible.
If you're in a hurry to be somewhere and are willing to pay someone to do the driving, surely it isn't too much to hope that they have also boned up on how to get there?