I live in Finland and here, we always take our shoes off when we're at home or at someone elses house. When I was younger (i'm 15 now so not anymore) we used to take off our shoes in school too. Why do Brits and Americans leave their shoes on? Floors get dirty, muddy and wet and it's just not as comfortable... Some people even lay in their beds with shoes on... It just doesn't make sense to me.
I'm not sure why, but I DO know that not every single person in Finland takes her shoes off and every single person in the UK and US doesn't. I'm completely sure in muddy places in the UK and the US (or in winter) do indeed take their shoes off when they come in the door.