If your holidays included a family gathering, you too may have spent some time with an older relative who speaks in clichés. In many cases, familiar old sayings are convenient as shorthand for sharing hard won wisdom. On the other hand they can be used to explain away unpleasant truths.
For example, if you asked why that one cousin just sits there and never contributes to the lively political or artistic conversation going on around him some family elder might have sagely said, "Still waters run deep."
But take a close look at Cousin Ned and decide for yourself. Sometimes, still waters are just stagnant.