One evening on my way home I was talking with Rob who observed that there was only one letter different between the words mastery and mystery. Rob’s observation came on the heels of acknowledging that there seems to be a thin line between the two. It's true, whether we're dealing with a relationship or enlightenment, mastery is often equated with demystifying things.
It might seem that the defining line however thin, would be knowledge, and that would be correct. But mastery does not land on the side with a lot of knowledge compared to mystery having none. The reverse is true in that while a master may have a great deal of knowledge, what is most useful is the awareness that knowledge -- attaining and maintaining it -- is what keeps us steeped in mystery.
With a little imagination we can see the “y” as a symbol of the questioning “why”. Asking “why” is grasping at knowledge which when unknown leads to the suffering of needing to attain it, and once known leads to attachment. On the other hand, mastery has an “a” which brings about the sound of “ahhhh”. Mastery is the relief of letting go and finally grasping that there is nothing to attain but giving up the effort of seeking to understand why.