Assumptions

I've been thinking a lot about communication-how to do it most effectively, what that entails, and how I can get better at it. One of the things that Court and I have talked about recently was how assumptions fit into effective communication. I will try and make this as clear as possible. When I am talking to someone about a certain topic, and they assume that I don't know something about that topic (when I actually might), and they begin to feed me the information as if I didn't know it, it clouds the effectiveness of our communication. I hope this makes sense. Have you ever been in a conversation, and you were both trying to say the same thing, but were both saying it in very different ways? That's what I'm talking about. I think this is where I could get much better at communicating more effectively-choosing the right words, in the right order, so that across the board (no matter who you are talking too), they do not assume something different than the message you are trying to get across. I think I say, "That's what I meant." way too often. What are your biggest communication frustrations?