[zorpner]

Sense of purpose. A huge part of life satisfaction is doing something that actually matters.

Truly, and it's changed my life for the better.

I'm unclear, however, on the relevance of this statement to the extant startup scene -- ref: the latest YC class, for example.

[icebraining]

There are quite a few health-related startups in the latest YC class that seem to be doing important, such as Hepatx.