Everything In It's Right Place

My problem is that I don't know how to completely, effectively express what I'm thinking. This, by all means should be a simple human task, though it's not. In conversation it's worse, but I see it in my writing too. I forget that you don't know my history and can't hear my internal monologue. So listening to me or reading my words is kind of like observing one side of a phone call. You can almost piece together the story, but so much is left to be explained. Without the explanation it sounds half assed and/or retarded. Eventually, it gets boring and irritating trying to make sense of it.
That's odd. I'm trying to explain how I can't explain things. Trying to write about not being able to write. So here I am. I need to clean out, repair and re-organize my head.