A friend of mine had two wonderful sayings.

He once said that he had reached an age where he was able to hold two diametrically opposing opinions on the same topic in his head at the same time.

Perhaps more sagely, he once told me that "having travelled through life I have reached a significant conclusion. Not always, in fact, not even very often, but sometimes, sometimes everyone else IS WRONG!"

The trick, I guess, is to know this at the time.