Which means it has to resonate emotionally or carry plot forward effectively or delineate character effectively. I have actually heard grumbles that a wise old man the characters meet will know things to help them. Like a wise old man who does nothing for them is plot-relevent enough to be mentioned. The death of the mentor -- how else can the student show he is his equal except by managing without him? With bonus points for providing a motivation, too.
Then again, cliches are notorious for having no resonance, for having all the emotion drained out of them by over-use. . . .
It can be hard to judge because it's subjective. Not just in how often you've seen it before, but how well it resonated for you. A cliche that carries a lot of punch for you can still be powerful when the cool kids are saying it's oh so five minutes ago.
