Tell me an event related to morality or law that you have experienced or seen and impressed you deeply or deeply.

Three people walked together, and one of them squatted down to tie his shoelaces, and we didn't care. We walked on, but after a while, we didn't see him catch up. Looking back, we were caught by an old man and quarreled. We hurried over to find out the situation and said that he had picked up the chess pieces. He is playing chess by the roadside not far away. One of his chess pieces was thrown on the road by his grandson and picked up by my friend, and others helped to pick it up. At that time, if we waited for a friend together, we could testify for him, but we didn't wait for him together and lost the opportunity to prove our friend's innocence.