I live in the United States and although I grew up here using Fahrenheit, I switched to Celsius almost 10 years ago. Part of my reason for switching was the rest of the world was using Celsius and every time they would mention the temperature, I had no clue if that was very hot, or just right and kept having to convert, so since there were not that many countries that used Fahrenheit, I switched. I still know what the comfortable range is in Fahrenheit, but now I also know in Celsius as I use it every day. Also, I no longer appear to be an old curmudgeon that is resistant to using a system the rest of the world already uses.