Where was the event that you found to be especially memorable? What details do you remember about the day? What was said by the speakers, who played concerts, who did you see there?
How did the forces of law and order behave? Did a confrontation occur? Were you arrested? Were you treated fairly?
How did the bystanders behave? If they tried to start fights, why do you suppose they did so?
What insights have you learned from your experience?