Thoughts
Have you ever been just sitting around and had a thought pop in your head. Where did it come from, was your mind thinking on it's own and you were just unaware at the time. The mind is very complex so I guess that it would be possible for your mind to actually be thinking about something while you are involved in doing something else.
While talking about thoughts, what about dreams, are they always something that your mind has been dwelling on that you consciously didn't know about or are they all just random thoughts put together while you are asleep. Sometimes a dream will make sense, like when you dream about someone that has died in the past, but then times they don't make any sense at all and you only remember bits and pieces.
Last if dreams and random thoughts are things that the mind is subconsciously doing that you only find out about every so often by accident or in a dream while your asleep, what all is your mind up to that you don't find out about.......