I like what Neale Donald Walsch says in the secret about purpose - there is no purpose in life except for the one you give it.
I'm new to Steve's work so I can't really comment on whether this sounds like authentic Steve or not...
The main challenge people face is they spend so much time wondering and worrying about what the purpose of life is, they forget to define a purpose for themselves.
Life is pointless! That's your blank canvas that you start with - you get to define a point if you want to! However there are no requirements - you do not have to be "good", happy or healthy. You don't even have to learn anything, although I believe that if you don't experience these things, you are choosing not to express who you really are.
It's a thought provoking post and it's generated some interesting comments here!