The highest purpose is to have no purpose at all. This puts one in accord with nature, in her manner of operation.
Mindfulness is a state wherein one is totally aware in any situation and so always able to respond appropriately. Yet one is aware of being aware. Mindlessness, on the other hand, or "no-mindness" as it has been called, is a condition of such complete absorption that there is no vestige of self-awareness.
When the mind is nowhere it is everywhere. When it occupies one tenth, it is absent in the other nine tenths.
How old would you be if you didn't know how old you was?