While you're getting frustrated, queuing up at the cab rank over the silly season, spare a thought for the poor drivers.
They're probably just trying to get their heads around the fact that their brains are growing.
Apparently, some scientists at London's Institute of Neurology measured the amount of grey matter in the brains of taxi drivers and other people. They discovered that the cab drivers had more in the part of the brain associated with memory, the mid-posterior hippocampus.
This is the first research which indicates that adult brains can grow when exercised.
So, there's hope for me yet. Now, if I can only learn enough street names to cancel out the loss of brain cells from my Bah Humbug partying ...