Fluids seem to be kind of split. Water bottles seem to be more commonly measured in milliliters (16.9 fl oz is just awkward). Smaller bottles of soda are measured in fluid ounces (16/20 oz bottles), but larger bottles are measured in liters (1-2L). Some hard liquor is measured more prominently in milliliters, beers are generally measured in pints, and we generally measure shots in fluid ounces. It's weird.
And yeah, Bobbias, I think in your case they're trying to teach the new kids metric a lot more heavily so that they can work to fully replace it. That's definitely not something that people are going to be able to adjust to very easily, especially if they've been dealing with Imperial units for 30+ years. From what I've read and heard about the UK they seem to be even more dysfunctional when it comes to measurements. They seem to use metric in quite a few places, though they still stick with miles per hour, and they seem to measure weight in stone (which converts more cleanly to pounds than kilograms).
I'm kind of wondering when we're finally going to start making the switch. When we do, I can't even imagine how long it's going to take.
One thing that I really don't understand is the switch from Fahrenheit to Celsius for outdoor temperatures in some areas. Fahrenheit is basically a nice and granular measure of comfort, while Celsius is based solely on the freezing and boiling points of water, something that's not entirely relevant if you're curious as to how nice it'll be outside. I suppose on one hand it's nice to try to keep the number of differing measurement systems down as low as possible, but in some cases it simply makes more sense to have different units.
I dunno, maybe it's just something that takes time to get used to, but, to me, 100F gives me a much better idea of how miserable I'm going to be when I walk outside than 38C does. And I know that when you're getting into negative degrees Fahrenheit, you're going to have a bad time, whereas the line is a bit blurrier when you're talking about Celsius.