In Australia we changed to the metric system in the 1970s when I was in high school. It wasn’t easy, always needing to convert. Went to uni to do engineering, the metric system made calculations so much easier.

And it’s all related: 1 litre of water has a mass of 1Kg, it freezes at 0C and boils at 100C, and has a volume of 1,000 cm^3 (cube measuring 10cm x 10cm x 10cm).

Even a gallon is a different amount from US gallons to UK gallons. That's where things spiral right out of control. He didn't even touch on that madness.

As a good Brazilian who always used metric system I never got so angry as when I was in UK and decided to make a dessert, found a recipe, and realized everything was in ounces, pounds, whatever, and after converting everything, and trying to be a good girl, I failed miseribly and my cake was uneatable. So I realized how much I really hate the imperial system. 😂 I wasn't trying to build a rocket, I was trying to cook.
Edit: you guys saying that must have been a very old book, the recipe was found actually on internet 😂😂😂

Using the Imperial system is almost as ridiculous as flipping the date and month to an illogical non-sensical order in MM-DD-YYYY

"180 cm" in Metric system;
1800 mm
 180 cm
     1,8 m

"180 cm" in Imperial system;
70,866 inches
  5,906 feet
  1,969 yard
  5 feet & 10,866 inches

Or

"1,5 yard" in Imperial system;
54 inches
 4,5 feet
 1,5 yard
 4 feet & 6 inches

"1,5 yard" in Metric system;
1371,6 mm
 137,16 cm
      1,3716 m

Conclusion: Anyone who says Imperial is as easy to use as Metric needs their head checked.

People are too harsh towards the US. They’ve been using 9mm in schools for a while now.

Every country had in the past its own measurement system. In Germany even every town had an own definition of length. My gandfather still counted in this crazy units. I am so happy that we changed to the  metric system 150 years ago.

To convert between miles and feet you remember "five tomatoes" because it sounds like "5 2 8 0", and there's 5,280 feet in a mile.
To convert between metres and km you remember "one thousand", because the metric system was not designed by a drunken lobster.

As an Aussie I am lucky. Because I am Gen X I was taught how to use BOTH systems and BOTH are very familiar to me. However, when I compare both systems it is VERY clear the metric system is much easier and simple to use.

What I really like about the way they defined the base metric units (the last being kg in 2019) is that they made it reproducible. Even if you are not on Earth, and all human artifacts have been destroyed, and the only thing left is the description of how to acquire the base units. You can still recreate the metric system. You do need some non trivial instruments for most of them, but it's nothing compared to needing the foot of a human king who has been dead for centuries.

I was in year 4 primary school in Australia when we converted. I found it so much easier. I went on to become an electrical engineer (telecommunications) and found it a breeze. I worked in the US for 6 months on exchange and my peers in the US wondered why I was so quick and accurate. I told them I work in metric and converted to imperial right at the end so our US cousins could understand the solution!

He didn't even get into how incredibly irritating it is to work in 1/8ths, 1/16ths, or 1/32ndths of an inch instead of millimeters. And having had to convert pounds to units of mass before, it is so incredibly annoying.

Oh and cooking measurements. A teaspoon is 5ml. A tablespoon is 3 teaspoons. 2 tablespoons is a fluid ounce. 48 teaspoons, or 16 tablespoons, or 8 fluid ounces, is a cup. Two cups is a pint. Two pints is a quart. Four quarts is a gallon, or 128 fluid ounces. Or 256 tablespoons. Or 768 teaspoons.

As a retired engineer the Metric system is miles better ( see what I've done ). Also I was fortunate enough to be educated in both Imperial and Metric.

I work in a Supermarket in the UK, it is all metric throughout, especially on the counters, the prices are in Kilos, and the majority of customers ask for things in grams, which is so much easier, I weigh a piece of meat, for example, it weighs 1kg, they want 250g, easy to work out, love the metric system, time we said goodbye to the imperial system, for our safety, and comprehension

I’m also an Aussie who went through the conversion. It was the best thing the country did to get rid of that ridiculous system. Nothing had a standard form so you had to remember how many ounces made a pound and a pint let alone rods, perches, furlongs, hundredweights, acres etc.🥺🤪

I'm Canadian.  We converted to metric in the 70s.  I am in my 60s now and it's hilarious to listen to a twenty something tell me they're to old to learn a better way.

My Dad was a yacht designer/surveyor for almost 50 years. We had bunch of charter boats called the Hylas 65. Sadly their masts kept falling down, which is rather dangerous. No one could figure out why, so Dad sent for the drawings from America and the construction plans from Taiwan. The US design was in imperial and, you guessed it, the Asian ones in metric. Someone had made a boo-boo on the calculations and he spotted the cock-up. Every boat had to have the masts pulled out for rectification, it cost them hundreds of thousands.

Americans are proud to remember that they were British colony that why they keep imperial system.

@ItsJps There's another video of a man designing houses in Australia. He explained that when he used to build a house using imperial, because of the imprecision, there's a full truck of wasted construction materials. Now he switched to metric, he mandated all his workers to get rid of their dual and imperial rulers, only use metric, and the volume of waste has been reduced to a single wheelbarrow for the same house

I remember that when Airbus started manufacturing its aircraft, some parts were measured in imperial units, and others in metric, conversions were made but when they tried to fit the aircraft parts, they simply did not match. They resolved the matter by defining that ALL measurements should be made using the metric system.