Or perhaps they've not been taught, how to read a map.
I'd agree with you Faraday.
From what I can see all the standard education system teaches them regarding geography (and history) is from the biased nationalistic view of all the bordering countries they were at war with centuries ago.
I'd say that most Thais can tell you the countries bordering Thailand due to that, and that's quite often as far as it goes.
Nothing to do with intelligence, but more down to the elite running the country discouraging them to think for themselves.
A few years before my wife bought an iPad (making it easy for everyone to use GPS) she learnt to read a map book and I encouraged her to navigate when we went on trips.
I remember years ago being in Chiang Mai and showing a tuk tuk driver a map of how to get to a hotel I was going to. His eyes glazed over, it was obvious he didn't understand the concept of a map. He more than likely had never seen one before. Not necessarily to do with intelligence.