We all have past, a place where we were before we knew Jesus. We may have memories that make us cringe in shame and regret, but that's not where God wants our focus to be. Because if we are so busy looking back at the past, then there is a good chance we will lose our balance and stumble on the path before us.
Paul when he was still called Saul persecuted Christians, then Jesus showed him the light on the road to Damascus. After that he became an apostle and brought the Word to the gentile nations. In the Old Testament, Rahab was a prostitute, but after finding God she turned her life around and became an ancestor of Jesus. Moses and David were both murderers, and David was an adulterer too. Yet if any of these people had kept their focus on the past and their personal history, they never would have seen themselves as the people God already saw: His children who, with His strength and help, would further His kingdom. Paul states it best in Philippians 3 verses 13 and 14,
But I focus on this one thing: Forgetting the past and looking forward to what lies ahead, I press on to reach the end of the race and receive the heavenly prize for which God, through Christ Jesus is calling us.
We are all just works in progress. Not the finished person, but definitely not the lumpy mess we started out as. Forget the past and press on to the place that Jesus is calling you.