it's a shame that your years of experience have taught you so much but failed to teach you diplomacy.
Au contraire, mon ami. Growing old had taught me a lot about the word diplomacy! I have learnt that what people call diplomacy, very often can be labelled as hypocrisy [simulation of goodness, pretence, not telling entirely how one's feel]
Collected from others:
Diplomacy is the art of telling someone to go to Hell in such a way that he would enjoy the trip.Diplomacy, the art of patting a dog with one hand while reaching around with the other to find a rock to club it with!