lost connection

somewhere between my brain and my fingers, I lose the connection.
I have great dreams of writing and have it all mapped out in my head, but once I try to write it, or type it, I lose all connection and it all falls flat.
Why does that happen?
In my head it flows and I know exactly where I want it all to go…..but somehow I lose it, between the brain and getting it down in book form.
😦
So disappointing…..