My purpose for right now, is to get through school, land a good paying job and help support my family. My purpose for being here has changed several times throughout my life. When I was little, it was to have fun and learn and be a kid. As an adult, it was (and still is) to be the best parent I can possibly be to my kids. It's also to be responsible and show my children how to be responsible adults. After my kids are grown and out of the house, my purpose will, no doubt, change again. So, for me, and many others, we don't have just one purpose that we go through life with. They are ever-changing, based on where we are and what we're doing in life.
Disclaimer: I am only responsible for what I say, not what you choose to understand.