Bean, I do the same. I work in metric, but I use imperial "measure exaggerations" freely, without even knowing how much they amount to! At the end of the day, I have only a vague idea how long a mile or a foot is. Fortunately, the new "European" Britain has had to turn bi-measural, so I can manage just fine. My British friends get all miffed about it, claiming that since I am in Britain I should learn to measure in imperial! Well, they can sit around and wait a bit longer for that to happen...