And it came to pass, when the time was come that he should be received up, he stedfastly set his face to go to Jerusalem. - Luke 9:51
Jesus was clear about His assignment. He was locked in. He "set His face like a flint" (he was stoned-face) when it was time to give His life. He knew His why.
What is your why? Why did God give you life? What is your unique configuration of grace and experiences which God can use to make a difference in the world?
If you have the answer to these questions, awesome! Write down your answer to the questions and use it as a guide for decisions. Use your why to decide where you invest time, talent and treasure.
If you don't have a clear "why?", take time to dream. Dream with God. Evaluate your desires and your story, and ask God to give you understanding of your life. Dream about the greatest impact you could have on the world, given your life up to this point. Dream about the person you want to be. Then, dream about the person God wants you to be. Are they the same? What needs to be realigned in your desires?
There is a universal why for every human being to reflect the glory of God. We all were created in His image and likeness. (Genesis 1:26) We all have the mandate to be conformed to His image. (Romans 8:29). And, you have a unique purpose and are meant to leave your own mark on the world. Only God can give you understanding of that mark; it's never too late to discover it.