What's the highest and best use of myself?

Let me start by saying right off the bat that this question is not easy to answer.In fact it's really saying "who am I?" and "what's my purpose?".I'd also say that many people don't know the answers to these questions and the very reason I am asking this of myself.
We all define ourselves in some way,and I believe we do this mostly with 'what we are'.In other words,our jobs,what we do,what we own,our labels we give in order to place ourselves in society.Of course there is nothing wrong with this,unless the tags we use to define ourself no longer work,give us a sense of who we really are,and give real meaning to our life's purpose.It leaves us with a void,or a feeling something is missing.That something missing comes from a feeling of want- I want a relationship,I want more money,I want a better career etc...and "want" comes from a feeling of lack,whereas you could say love and desire leads to passion and energy.
So,doing something you love is a big step in leading a life making the best use of oneself.And if doing what you love serves a higher purpose this gives to the world rather than takes.This is a big clue in finding fulfillment.
Truly successful people are those that have resolved in their minds their true purpose in life and have committed to that purpose.It's their driving force,their reason for getting out of bed in the morning.
So,what's the highest and best use of myself? Only self can answer this,but as the saying goes "follow your bliss". If you don't know what that is,make a committment to find out.Open up your awareness about yourself and what you really want.Align yourself to the truth of who you are.
I've merely scratched the surface on this topic of "purpose" but hope that by merely asking the question a curiosity and piqued interest will lead to some benefit...who doesn't want a rewarding and enriched life? What can we do to lead this?
In future posts I hope to answer these questions and more...