Some people seem to think in either metric or imperial measurements and can't comprehend the opposite. Other people can think interchangably in both. I'm a really messed up version in between.
I measure small things in either inches or cm depending on my mood. I know my measurements (bust, waist, hip, etc) in inches but not cm, but I buy fabric by the metre and can measure a metre of fabric out incredibly accurately on my arm. I use a 1.5cm seam allowance for garment sewing, but a 1/4 inch one for quilting. Heights are always feet and inches, metres means nothing to me. Medium distances (for example ones I could walk or cycle) are in km, and my brain just doesn't fathom big distances.
Weights are just the same. I don't get on with "cup" measurements, and my recipes are a bizarre mixture of oz and grams, litres and pints (even within the same recipe sometimes). However, weights of people I can't comprehend unless they're in kilos.
What kind of measurements do you think in?
(this random post brought to you by my new tape measure thats 3 metres long!! and even better only $2! (from GJs))