I am alive today because someone close by me knew how to do this. I hope others never need to use it, but I hope everyone 'knows' how to use it.

Yes. Probably one of the best quick hits in first aid. By comparison, while CPR is good to know, it's probably only going to help in a fairly limited set of circumstances.

One of my complaints about first aid courses that I've taken is that they seem to spend a lot of time on things like splinting and often skip lightly over stuff you're more likely to run into in everyday life.

Also have a look at the video on how to do it on yourself.

Me too. He was six at the time. A hard candy he took from a restaurant.