Actually, this is a great point. As someone born and lived almost all my life outside the US, I just couldn't understand the Fahrenheit system. Having spent the last few months in the US, I went the opposite way to try and force myself to understand Fahrenheit and what I found was very surprising.

Fahrenheit actually makes sense if you consider it from a weather perspective. The only way to use the Fahrenheit scale is to look at it as percentage of body temperature. Now, I know that the body temperature isn't 100 but 98.4. If you keep that part aside for a minute, it's very easy to explain the Fahrenheit scale. 50 degrees is 50% of your body temperature. 32 degrees is 32% of your body temperature. 100 degrees means that weather is equal to your body temperature. That means things like if the weather is hot or cold is just percent of body temperature. Also, 0 degrees is the temperature at which brine freezes. So, no matter how much salt you add, ice will not melt.

Historically, when the Fahrenheit scale was invented, body temperature was supposed to be at 100. It was later realized that the body temperature is slightly less but no correction to the scale was made.

Every other scale makes no sense to me. I convert pounds to kgs, miles to kms, gallons to litres etc.. all the time just to get a sense of measure. But for the weather, Fahrenheit is really good.