You don't want to use your left hand to hand anybody any element. "Hand me that piece of paper, will you?" You'd better remember to use your right hand because that's what they do there, that's the protocol they use with you and amongst themselves. The reason? Somebody told my friend that they use their left hand in the toilet, but... we're not really sure whether that person was pulling Isa's leg he was serious. things out with one is seen as respectful, less assertive gesture, so they put left hand behind their backs Honor this their custom by doing the same!