On identity: Am I still South African?

I always know when there's something bothering my children. The indicators are fairly simple really: like the flurry of questions or the rhetorical statements made the minute they walk through the door. My son's most recent bother was one that questioned his identity.
"Mommy, am I still South African?" was the first thing out of his mouth- before he had even put his school bag down.
"Of course you are! Why do you ask?" I cautiously ventured, hoping it was not going to be one of those answers that required a clinical psychology degree. Sometimes I simply do not know how to make his hurt going away, and worse still at times I just do not have the answers, and yet in my son's eyes I am the well of all knowledge - me and Wikipedia.
"Because the South African on the bus said I'm not." He references all the children on his school bus by nationality, even though he know their names. I don't know why and have never asked. He just does. Maybe it's the thrill he gets each time there's a new nationality that joins his bus route (I do know that this is a real thrill for him because he is always quick to excitedly update me if there are any changes in the country representation); or maybe he likes the idea that in any given school term, there are always at least 8 nationalities on his route (this is a 10 seater bus).

I still remember his excitement when he came back from school at the start of the school year: We have a new South African on the bus. Having another South African on the same bus route was like finding his kindred soul at long last, but now I could see that the glow of camaraderie  towards his compatriot was fading fast.
"He says that because I have not lived in South Africa for a long time, I am not a true South African.''
I will not even go into the emotions of anger evoked by that statement. But I held it together and remained reasonable in my assessment of this point of view. Okay, fair enough - we left South Africa when my son was two and a half years old. After three years in Ghana he was proudly claiming his dual South African - "Ghananaian" nationality . He identified that much with Ghana. He had a wider Twi vocabulary than a Sotho one, and mannerisms that spoke volumes about his partial West African upbringing. In France, after almost three and a half years, he declares his South African nationality without hesitation. So all things considered, it is having spent a good part of his life outside of South Africa that calls into question his nationality.

I think I have risen to the challenges of raising my children outside their country well enough. They know not to address adults by their first names; they know how to greet; they can understand their mother tongue  - although speaking it is still a problem (perhaps my biggest failure yet);  the flag colours; the national anthem (sort of); past and present presidents...let's just say the Encyclopedia Of All Things South African has been a real help. I order my Iwisa Maize Meal , biltong, and Mrs.Balls chutney from the South Africa online store every so often, and put together a real South African meal for the International Days at their respective schools - working with what I can find from the Monoprix. And with the help of gifts from my dear friends back home, they don their seshoeshoe shirts or beaded ndebele skirts and set off to show off how proudly South African they really are. Then the 'South African on the bus' turns around and questions all of this.

This had me thinking about whether when we return home, they will encounter this sort of narrow thinking on a regular basis, or if it was simply the misplaced view of a sixteen year old to an eight year old who didn't have the vocabulary to defend himself. It is difficult enough for third culture children to get on in the world, when they themselves question where they belong all of the time, without the added pressure of possibly being 'outed' by their fellow countrymen. I am still not changing tack though, proceeding as before. But now I am adding to their repertoire of life skills: 'How to defend yourself (verbally of course) if ever your identity is called into question'. I believe that  one will be an ongoing lesson.