Sustainability (derived from the Latin 'sustinere' (tenere 'to hold; sus 'up'), is the capacity to endure, to continue to hold up one's objectives in the face of life experiences that may pull one down or cause one to lose focus. Paying attention to my desires (rather than my fears) is my focused objective.
A quote from Mike Dooley (tut.com) is helping me to remember what to pay attention to: "Life is where one goes to temporarily believe in death, fleetingly forget their power, and briefly have the Dickens scared out of them, voluntarily. All in the name of adventure."
I like the thought of being an adventuring volunteer on this journey.