Who Controls our Thoughts?

If we are so in control of our lives, then why is it so problematic to silently count to ten or twenty or a thousand in our heads without another thought intruding?

And what about that intruding thought?  Where did it really come from?  Did we as an individual entity create it, wish it into being or did it just seem to appear randomly across the screen of consciousness?

Or how about the silence/space between thoughts, emotions and sensations?  Do we somehow control this silence/space or does it appear on its own?  Do we control its appearance?  Do we control the silence or space between things?