Londoners, it has to be said, have a love-hate relationship with black-cab drivers.
Normally, the extent of the love and/or hate is directly correlated to the weather conditions and whether you are in London or some other capital city.
For example, find yourself in London on a rainy night wanting to go to Bromley, and your quality of mercy is most definitely strained.
First you will never find a cab with a light on and, if you do, you will be told that you have absolutely no chance of getting to Bromley in a black cab.
This is because Bromley is more than six miles from Charing Cross, and once you are outside that line, a cabbie can (and, if it's raining, probably will) tell you to bog off.
Londonist has known about the six mile rule for a while, but we never knew its origins. But now thanks to Transport for London, we need wonder no more.
The rule exists because (and you are going to like this one) six miles is the reasonable limit for a "horse-drawn hackney carriage carrying four people and their luggage".
In other words, even if your cab was being pulled by a horse, seven miles would be no problem if you were on your own and not going on holiday. But tell that to a cab driver and will they listen?
But the same press release does make us realise why, as soon as we get outside London, we rediscover what a joy cabbies are.
For only London has “the Knowledge”, 320 'runs' which cover the whole of central London and the interesting (and not so interesting points) therein. And if that's not enough they have to memorise all the places within a quarter-mile radius of both end-points.
But want to know the really weird fact about 'the knowledge': apparently a cabbie’s brain physically grows during the learning period.
Now that explains a lot.