That is interesting. I don’t really have a mental visualization for the concept of “year” at all. If I had to try I guess I’d just imagine a calendar (twelve month-pages).
I wonder if visualizing a year as a circle is a particularly Norwegian thing, or if I’m the odd one out anywhere…
Back to the subject of which day the week begins: I’d say the fact that the week begins on Sunday doesn’t have much of a meaning in US culture, if any. If I say “next week” at work, it clearly means “the next M-F period”. If I wanted to refer to Saturday and Sunday I’d say “this weekend”. So if what I normally mean by a week begins on Monday and ends on Friday, you have to slot the weekend on one of those ends, and it feels slightly wrong whichever way you do it.
So, the only practical, concrete way in which “the week starts on Sunday” means anything to Americans is that we are used to seeing calendars printed with Sunday on the left, and Saturday on the right. I continue to maintain that this is arbitrary! But it does make me really confused when I have to use a calendar widget in an interface that wasn’t localized, and starts with a day other than Sunday, so I get your frustration.