My science education, at least in secondary school, was all in metric. I graduated from high school in 2003. The issue is that it isn't used here in everyday life, so it becomes "that weird thing from science [which I already disliked because of the math]".

I've done experiments switching to metric. It's not a good idea to rely on my GPS for speed limit information. My home thermostat apparently doesn't have a Celsius setting (and would confuse my wife if it did). It's difficult, but mostly possible to switch here...but what's the point? It's a lot of work for comparatively little benefit.