John Ebdon's books about Greece, and the wave in Greece

I haven't looked at these books for ages.  They came to mind when I was reading about the gestures made in the Balkan - a nod means no, a shake means yes.  In one of his books John  Ebdon described meeting an old Greek man riding a donkey.  John Ebdon waved a friendly greeting at the elderly Greek chap, whi in reponse turned on him ferociously.  Greeks these days are used to gestures froim elsewhere.  But showing the palm of your hand is a very offensive gesture in Greece.   And when you give someone a friendly wave what do you do - show them the palm of your hand.  Sometime in Greece I do give a wave, and when I realise what I am doing, I rapidly turn the palm of my hand so that it faces me - which must look odd in itself!