You could say 'you' are being mindful for the sake of convention, but really nobody is being mindful. There is no core or central part which is mindful. It may seem like 'you' are watching, but the watching is a process that just happens by itself.
Right effort arises not from a controller, but from having a right idea. This idea then comes from insight or faith or intuition - all factors that are again dependent on other things. Things all arise dependent on condition, including the eightfold path itself. There is no need for free will for the path to be developed. Also there is no need for free will for there to be wholesome and unwholesome effort.
To let go of this sense of control in my experience allows the meditation to go deeper and beyond control. There it becomes clearer that it all happens by itself.