While stereotypes about a set don't apply to all members of that set (of course), they are more often than not more applicable than they are for the general population.

As such, it's interesting that your last name is a common one in Norway.

As it goes, what's the difference between a Norwegian introvert and a Norwegian extrovert?

When a Norwegian introvert talks to you, he stares at his shoes.

When a Norwegian extrovert talks to you, he stares at your shoes.

There are e.g. probably very few Americans who would feel "seething, ulcerating rage" at merely the offer of conversation during a flight (as long as they can reject it, and that rejection is accepted).