(This is an article by John Fischer, found in Contemporary Illustrations for Preachers, Teachers & Writers.)
I have a bad habit. When my children tell me about something they've learned for the first time, I often act as if I knew that. Even worse, sometimes I tell them how the same thing happened to me years ago.
When my wife hears something "new" from the kids, her mouth drops open and her eyes widen. It's as if she has never heard this kind of thing before. The kids' faces brighten, and they feel as if they have actually enlightened their mother.
I used to think my wife was just acting and sooner or later the kids would find out and feel lied to. Then I realized it isn't an act at all. Though she may have already experienced what they are trying to tell her, she's never experienced it through them. Their personal "revelations" are entirely new.
It's the same with God. As all-knowing and sovereign as he is, I'm sure he's still eager to hear our prayers because he has never heard it quite the way we say it. We are all unique. We have our own signature attached to all we do and say. Our lives, our experiences, and our faith expressed to him are never old.