Words are like fashion or music. If you hear or see something too often, it becomes passé or very "last year," like pointy shoes or a Gwen Stefani song after a few weeks on the radio. (On a side note, I'm not making fun of people with pointy shoes. I have a pair, acquired too late, and I've only been able to wear them once and I'm quite sad.)
But back to words. Phrases that are so overused that they become shells of their former selves. When someone uses a cliché, you know what he or she means to say, but you don't give it much weight because the words knock against your ear without really getting inside, to make an impact.
That said, I think clichés still have their value. When a phrase becomes commonly used, it's a good form of communication because people instantly know what you are talking about. There's no ambiguity. Like when my running group met last weekend to go over our game plan (another cliché!) for Sunday's marathon, we decided that although we'd been training as a team, on the day of the marathon it would be "every man for himself." That's a big-time cliché, but it's also an efficient way of conveying the idea.
And sometimes, clichés just say it better than anything else. Like this morning, I was thinking about whether I'm more or less marketable because I don't have any great skill, like finance. I went back and forth and then, to cheer myself up, I thought: "The world is my oyster." Now, I know that phrase is pretty worn. But I liked it anyway and it made me feel better.
On another note, there are 3 days left until the marathon. We've been advised get enough sleep and increase our salt intake. I love both salt and sleep, so ... Aye aye, captain! I'm on it. You don't have to tell me twice.*
*These are all clichés. I don't really talk like that.