I had a surreal experience once. I was at a busy, casual restaurant at a booth, sitting across from my wife. There was a lady eating alone at a booth a little way behind my wife, and I noticed she looked kind of distressed - looking around like she was trying to catch a waiter - but she seemed to be getting more panicked looking and her face didn’t look right. I got up and went over and said “Are you chocking?” and she looked at me with big eyes and nodded. I asked if she wanted me to try and help and she said yes and stood up. I never learned how to do the Heimlich except from TV shows, but seemed worth a try, so I did what I remembered, and she coughed up a piece of chicken. She looked really embarrassed and said “Thank you.” I said I was glad to help and went back to my seat. No one in the place noticed a thing except for my wife.