I wish we could just use metric.
With work pressures really get annoying as kPa, Pa (ok, understandable using both of those), bar (why not just use kPa or MPa?) and psi are all common. The 2 models don't even use the same units. Luckily no mmHg.
I know houses by square feet simply because that was standard. Before checking out some showhomes I wouldn't have been able to estimate. I could have just as easily learned square meters, but that's not the information that was given.
If I had kids I think I would be teaching them their weight (technically it's mass) and height in kg and cm. I have a pretty good idea for the range right around me, but if someone is about 300 lbs I would have to think what that is in kg - I wouldn't be able to look at someone and be like oh yeah, they are around 125 kg.
Then there is the old celtic stone as a measure .. so much blarney ... the stone of scone is a heavy bread meant settle the soldier in at home ... one hard broadvision? X Pan Sieve ...