I guess you don't really think about standardization until you experience a different standard somewhere else. Of course there are the standards that everyone knows about like flipping the switch down to turn lights on here, imperial vs metric measurements, and driving on the left instead of the right but it is the little things that are unexpected.
Beds: Single beds here are what I would think of as the width of a cot. They don't really have twin beds. The next size up is a double bed which is literally the size of two single beds, so a little wider than full size bed but not as big as a queen.
Gas ovens: This was the big one for me. My oven has the temperature in Celsius but apparently judging by cooking instructions on packages there are ovens out there with 6 settings. So directions just say set you oven to 4. I guess it's easier to remember than 350.
Windows: During the summer I didn't like waking up at 4am with the sun so I went out to get some curtains. Apparently there are a limited number of window sizes because when I went in with the measurements all I need to know was that I had a size 3 window.