I really don't understand difficulties with metric and Imperial measures, I've been using them both for more years than I care to remember (since long before Trudeau metrified us). High school physics and chemistry was all in metric in the 1960s and the only people who had any difficulty with it were also the ones who had difficulty with the basic subject matter, there's nothing about metric itself that's particularly difficult. And with a little thought you can easily invent shortcuts to comprehension. 60 mph, for instance, which used to be almost universally the speed limit on highways, is a mile a minute, so if you see a road sign that says "Podunk 42" you know it'll take about 42 minutes to get there. On the other hand, if you're going 100 km/hr and the sign says "Podunk 67" you know it'll take about 0.67 hours to get there, round that to 0.7, times 60 minutes, = 42 minutes. You can get a quick estimate of a Fahrenheit temperature from Celsius by doubling it and adding 30, and vice versa of course, Fahrenheit to Celsius, subtract thirty and halve the result, it'll be reasonably close over most temperatures you're likely to encounter. The liters per 100 km thing is confusing not because it's metric but because it's a bad choice of units and it reverses the scale of the old miles per gallon calculation, bigger is better for the latter, smaller is better for the former. Km/liter would have made more sense to me. And if you look closely at the labels on things you'll see that a lot of conversions are soft conversions anyway. Buy a jar of pickles, it might be a liter, it might be a U.S. quart labelled as 964 grams or 959 ml or an Imperial quart labelled as 1.14 liters, depending on where it came from. The government was a little bit sneaky about the conversion too, toothpaste sizes were converted before any announcement was made, and nobody noticed.
And scientific calculations are a LOT easier to do with metric units, you won't get confused about things like the difference between a pound force and a pound mass and the introduction of units you've never heard of, called slugs, to clear it up. Which doesn't work, it just adds another unit to remember that bears no neat factor of 10 relationship to other units the way metric units do.
