If the heart wanders or is distracted, bring it back to the point quite gently -- and even if you do nothing during the whole of your prayer but bring your heart back, though it went away every time you brought it back, your time would be very well employed.
I am not sitting, I am on a journey. Spiritually we are always on the move. We are on a journey through the inward spaces of the heart, a journey not measured by the hours of our watch or the days of the calendar, for it is a journey out of time into eternity.