It's possible! We can switch! I'm US born and raised and I voluntarily switched to metric in college. It took me maybe we few months to start building an intuition for Celsius, grams, liters, and meters. And that was with me in isolation. I would imagine it would be much faster if everyone else was also transitioning.
Over the years, other people have asked me about this and I've been shocked at how many people don't realize most of the world uses metric. Someone asked why I was using "Mexico units" once... Also, I've met lots of people who think the US invented inches, pounds, etc, which is... uh... interesting. The arguments y'all are having here are way more advanced than what I've run into.
For anyone who wants to voluntarily switch, I highly recommend not to convert between imperial and metric. Just read the metric number and that's it. The weather says it's 25c outside? Don't convert to F. Go outside, experience 25c. Over time you'll build an intuition. Smartphones and computers have made the switch easier these days.
Of course, until we all switch you'll really end up being bilingual...
For me it was particularly easy as it's only Chevy and Ford cars that still use the imperial system for nuts and bolts so I've been making use of the metric system for pretty much every car I've worked on and I never really understood ferinhight to start off with as I only really cared about is it going to snow temperature wise so why memorize a number for something your only going to check one time in the year now that I've gotten accustomed to Celsius I'm now paying attention to if it's going to rain or not
Question: I know that Celsius is one of the accepted SI units, but is it really metric? (SI includes a number of definitely non-metric units.) And, if being expressed as a decimal number is enough to qualify it as metric, then isn't the Fahrenheit scale also metric? It is also decimalized, and also defined in terms of the SI unit (Kelvin).