Hot on the left

The taps in our bathrooms don't have any sign on to say which is hot and which is cold. I presumed it had fallen off, or something like that.

Then, a couple of days ago, I realized that every tap I've seen here has the hot on the left. I wondered if that was some sort of massive coincidence - it's the sort of thing I can never prove (in a Popperian sort of way). So I typed "hot on the left" into Google. And it's true, in America, they put the hot tap on the left.

How sensible is that? Why doesn't every country do that?

I also learned that the brakes are the other way around on American bikes - the back brake is controlled with your right hand. I never really noticed that was the sensible way around to do it, until I moved here (with my UK bike) and realised that when I want to turn left, which is across the traffic, I need to brake with my right hand. My left hand is busy indicating, so I need to use the front brake. It would be nicer to use the back brake. I'd change them over, if I thought I'd ever get used to it.