INFPs, more than other iNtuitive Feeling types, are focused on making the world a better place for people. Their primary goal is to find out their meaning in life. What is their purpose? How can they best serve humanity in their lives? They are idealists and perfectionists, who drive themselves hard in their quest for achieving the goals they have identified for themselves.
Yeah this is definitely true of me. While I don't generally prefer the company of others, I am very aware of wanting to make a contribution to the world with my life. It's probably why I keep striving to find something better to do with my life than be a receptionist. Not that that's a bad job, but it never felt like one that really meant something in the greater scheme of things.
Doing a job, for me, is more about making a difference in some way than it is about getting a paycheck (although that's nice, too). It is often speculated in INFP forums that life would be best if money weren't even an issue and people could just do what they're best at doing and enjoy doing most without needing to worry about whether or not it made enough money to live on.
So what is my specific purpose in life? My gut instinct tells me it has to do with being creative, so that's the direction I'm flinging myself in. I continually check in with my gut and with God to make sure I'm flinging myself in the right direction, but so long as I keep feeling confirmation about that, it's not as important to me that I know my end destination in life, so long as I'm pursuing the direction that feels like it'll be able to get me to a place where I'm able to use my talents and passions for a greater purpose. Make sense? ;)