In Australia, the official units for pretty much everything are metric. Road signs all have distances in kilometres. Temperatures on whether reports are always degrees Celcius. Unit prices on fruit and vegetables are always in dollars per kilogram. The price of petrol (not "gas", BTW) is displayed in cents per litre, and the fuel consumption stat for cars is typically given in litres per 100 km. Schools teach metric units more or less exclusively.
Most Australian adults have some awareness of imperial units in various contexts, though from the above discussion it seems that we use imperial units even less than Canadians (who, of course, are forced to share a common border with the United States). One reason we need some awareness of imperial units, other than for the purposes of interpreting historical sources, is that we all live in a globalised economy, with lots of international trade. We are also forced, from time to time, to communicate with more backward peoples, such as Americans.
If we buy nuts and bolts made in America, sometimes they have nice metric diameters (which is the most common these days), but sometimes they still come in fractions of inches and similarly nonsensical measurements, so we have to understand the difference and how to convert if necessary.
The baby boomer generation in Australia grew up with imperial measures - heights of people were in feet and inches, weights were in pounds, money was pounds, shillings and pence. Their children - generation X and those following - largely grew up in the metric era, after the currency was decimalised and weights and measures metricised. However, we still have to be able to communicate effectively with the boomers. If a hospital wants to know your height, their form usually wants it in centimetres, but chances are good that most people also know their height in feet and inches, even if that's virtually the only thing they use feet and inches for.
Given my education and upbringing, I personally never developed a good feel for lengths in feet or miles. I'm aware that a foot is about 30 centimetres, because school rulers and such things usually have both scales marked on them. But I can't look at the height of a ceiling and tell you the difference between 10 feet and 12 feet by eye. On the other hand, I have some intuitive sense of how far 100 metres is, or 3 metres. I'm also aware that 1 yard is approximately 1 metre, so I can do a rough conversion of metric to imperial or vice versa in my head if I have to. My internal length sense is calibrated for centimetres and metres rather than inches and feet, however.
When I hear or read reports of temperatures in the United States, I invariably have to do a mental conversion to Celcius to get a sense of what it means. "90 in the shade" does not immediately say "hot" to me, whereas anything over 30 (Celcius) immediately does, for me. "-10 degrees Celcius" says "freezing" to me much more immediately than "10 degrees Farenheit". I know my fridge keeps things at about 4 degrees Celcius; I have no idea (without calculating it) what that is in Farenheit.
Cooking recipes tend to get handed down from generation to generation. New cookbooks in Australia usually have volumes in millilitres, although measures like "cup" and "tablespoon" make some sense and are still widely used. I can tell you that a standard "cup" is about 250 ml; I have no idea what it would be in pints or quarts or whatever (without looking up the conversion).
A standard "pot" of beer (aka "midi" and other terms, depending on which Australian state you happen to be in) is typically 250 ml, too, these days, but it's also easy to buy beer in a pint glass (if you want a larger beer). I've never bothered internalising what a pint is in millilitres, because I've never found a need to to understand it in any context other than buying beer.
Buying "gas" in America in dollars per gallon was always meaningless to me (although I was keen to convert US dollars to Australian dollars to find how much the fuel was actually costing me). I don't do distances in miles, or speeds in miles per hour, so that also meant a certain loss of intuition when driving in the States.
Younger Australians have even less use for strange imperial measures than I do.