One of my main reasons for choosing "Australian National Identity" as the subject of our course here comes from Centre College's extensive experience with study abroad: when they study out of the country, our students discover that they are Americans. (Except the international students, of course, who already had a parallel experience by coming to Centre). Americans probably do proclaim their Americanness to one another more than the citizens of most nations do. Still, there are dozens of distinctive expectations that we have at home without knowing it. These American expectations and assumptions come out by contrast in another society.
Today we had a stellar day with a group of sociologists at LaTrobe University here in Melbourne. Kerreen Reiger had organized a day with her colleagues, most notably Peter Beilharz, Karl Smith, and Sue Turnbull. They helped us reflect on Australianness. They also confirmed that their students think even less about their national identity at home than Americans do -- but discover that they are Australians when they are abroad. Several of the professors, likewise, reported that they only had reason to describe themselves as Australian when abroad.
I don't think this fact means that national identity does not matter at home. I think it just means that national identity is most salient when compared to other national identities.