Celsius is pretty easy to wrap my head around, even though I think in Fahrenheit. I think my main argument against Fahrenheit is when I'm cooking and look up food safety information I usually convert to Celsius in my head because I have a pretty intuitive sense of temperatures as a percentage of the boiling point of water but Fahrenheit I really don't. I also don't imagine anyone using Celsius as their "native language" routinely converts to Fahrenheit in their head just to get a better understanding of what a temperature means.