Yes Charles, (that's a usual human "yes"
)
You're perfectly correct. In fact, I was even trying to look up a better English word than "shake" in the dictionary but I failed - you don't have any other one to convey negation (neither do we BTW). By "shaking one's head" negatively, the English and
the rest of the world (oh, those imperialistic lingual relics!
) imply
glRotate(+/-20,0,1,0)
a few times and that's only natural and clear for all other earthlings but Bulgarians. They would convey negation by a one-time nod
glRotate(-/+20,1,0,0)
while their agreement would be conveyed with a one-time tilt
glRotate(-/+20,0,0,1)
of their head to their left shoulder, both gestures being performed invariably in that particular polarity.
It's almost impossible to communicate with a Bulgarian waiter in a restaurant; you have to ask them again and again until they would vocalize their answers.
But in ordinary life it's a convenient and customary simplification to say that Bulgarians just do it "the other way round" compared to us ordinary mortals.