Paul speaks three times (chapters 22, 24, and 26) in the closing scenes of Acts. All three times we see him telling the story of how he was rescued by Christ from his life of self-righteousness and anger.
In this section, Paul told his story before the elders and crowds of the Jews. Later, he testifies before Felix (24) and Agrippa (26), both rulers.
Here's my takeaway: be ready to tell my story whenever the opportunity presents itself. Sometimes it will be among some pretty rowdy people and you won't expect the circumstance. Sometimes you'll have more time to think and prepare. Either way, it's critical to open your mouth and tell your story.
Great things await when we do.