Of course, the fact that we're still "self-employed" at the moment contributed to the fact we were out of touch. But mostly, I think it is because we don't have children. If we had kids at school, there is no way we wouldn't know which weekend was Easter, or when school holidays begin. The calendar would rule our lives.
I kind of like the fact that we are free and easy, and not enslaved by the calendar. And it means we can have more hot cross buns tomorrow too!