Temperature: I use centigrade (not Celsius, please) for temperatures approaching freezing, and Fahrenheit for hot days. Anything in between, I haven't a clue.
Length: I'm bilingual as far as centimetres and metres / yards, feet and inches go - but can't be doing with kilometres. People, however, are measured exclusively in feet and inches.
Volume: I memorized "A litre of water's a pint and three quarters" from the back of a Rice Krispies packet, circa 1972. But that's all I know about "metric" measurements of volume. (How did the decimal lobby get to bag the word "metric", by the way?)
Money: Okay - I have successfully moved to decimal currency over the last forty years, but I increasingly believe it to have been a mistake as far as the nation's capacity for mental arithmetic is concerned. And I'm still more inclined to say SIXpence than six PENCE. It saddens me that no new names have arisen to rival 'tanner', 'bob', etc.
Weight: For food, I use pounds and ounces, and work on the rough idea that a kilogram is just over two pounds. For people, of course, it's stones and pounds. Kilograms mean nothing in that context, while giving the weight in pounds alone triggers a hasty sum involving the fourteen-times table.
But now we come to it. When crossing the road, I naturally use the Kerb Drill (the military ethos of which quite passed me by), and feel that the Green Cross Code is an upstart interloper.
For this reason, I can never warm to David Prowse, whom I first knew and disliked as Green Cross Man, long before he was Darth Vader. Perhaps that's why I found Star Wars only mildly entertaining rather than a major cultural event: the spirit of Tufty was strong in me, and wanted revenge.
(Having said that, I do sympathize with Mr Prowse. Why it's impossible for a supervillain to have a Bristol accent is a mystery to me.)