Survivors Obligations?

I came across this whole presentation that Lance Armstrong did about the obligations of the cured.
I watched the "highlight" portion but I cannot dedicate another 55 minutes of time to watch the rest. I've gotten what I needed.
So am I really obligated? I feel like I am. Maybe that's another self-preservation thing that one's mind fabricates after traumatic events. Does being here to share my story and potentially help/warn/comfort another human being make what I went through more meaningful and less mindless. Is it possible to justify going through cancer for some higher purpose?
Listen, I have been very open I think and I try desperately not to wear people out on the whole "I had cancer" thing. But I did. It's up there near the top of the list of life-events that form who I am. Motherhood, marriage, cancer… check. But is it my 'job' or a calling to be helpful by sharing my story.
Seems to me that the biggest contribution a survivor can make is just to be healthy and move on. I didn't know enough survivors when I was diagnosed to KNOW that it was possibility and not just a fairy-tale dream that I might have a life after that diagnosis.
I hear you Lance. I walked out the same door at the hospital that you did; front and center. I didn't win the Tour 7 times and I don't have a global platform. But is his story too intense for the average Joe Cancer Patient? Even if it is, I'll keep my yellow band and I am grateful for the things LIVESTRONG does.
I don't know, but I'm thinking about it.