While Paul sat in Rome under house arrest in 61 AD, he had time to think about lost opportunities and mistakes he had made. As he considers his loses Paul writes to the Philippians that there is one thing he must do:
"But one thing I do: Forgetting what is behind and straining toward what is ahead."
Paul considered himself called by Jesus for a purpose, and Paul considers his role is to pursue the fulfillment of the purpose Jesus called him to:
"I press on to take hold of that for which Christ Jesus took hold of me."
Paul had done incredible things by 61 AD which would include his ministry in Antioch, the Jerusalem Council, his work and letter for Galatia, three years at the Ephesian church, starting churches in Macedonia and Achaia, Greece and much more. But, even with that record of successes Paul is still considering his life and ministry far short of what Jesus could expect and what Jesus had planned for Paul. Paul writes:
"Not that I have already obtained all this, or have already arrived at my goal, but I press on to take hold of that for which Christ Jesus took hold of me."
Paul saw his Christian life as a race with a reward at the end. In a race a person can get tired, distracted, injured or, even, quit. Paul plans to continue disciplining himself for the prize that Jesus has prepared for him as a reward for having fulfilled the purpose for which Paul was called. In fact, Paul says he is "straining" and "pressing" for opportunities that are yet ahead of him:
"Forgetting what is behind and straining toward what is ahead, I press on toward the goal to win the prize for which God has called me heavenward in Christ Jesus."
For sure, Paul says he has made mistakes, but he can only learn from them and then foget what is behind, because the only opportunities he has to finish his race, fulfill his call and achieve the reward is in the future. So, Paul forgets about the past and presses on into the future determined to make the most of each opportunity God will yet give him in order to complete the purpose that Paul was called to for.