When someone tells a boring story that nobody else cares about. Its usually long and/or takes forever to get to the point. It may have no point or doesn't say anything important that anyone cares about. It is a form or rambling however the person does not realise they are doing it even if others have tuned out or is looking back with a blank stare. If the story had already been told it is refered to as a stale pastry.
This is a short pastry spoken by a colleague who I work with every day: "Today I walked to work along the footpath past many houses as I do every morning. I have to stop at the pedistrian crossing. Then I got to work, I walked inside, said hello to you and sat down to work"