Thanks dear Vertigo for bringing up this great topic.
For me, the circle area of my interests and passions have been shifting and shrinking for some time ... partly by physical and mental new limitations and partly by consious realization and diffrentiation of what really matters.
Only the other day, I was desperate and felt life has no purpose or meaning .. my body was shivering .. I was crying ..
Today .. I feel the wonder of life .. the light shines .. and I can enjoy it's music .. I will work on it ..
You need a belief .. a blind belief .. beyond reason or logic .. IN LIFE..
To the very end .. like a devoted Yogi, I will breath the air and think that is enough if be it !!