Yes, I have. It was a few years ago when my family and I went on vacation in Spain. There were many people on the beach that day. However, I noticed that one guy near 4-5 years old was alone and cried. I asked him what had happened and he told me that he had got lost and could not find his parents. Together we asked his parents for approximately half an hour and finally found them. They thanked me, and I went back to my family.