Learn first aid with education resources, advice and courses from the British Red Cross, including first aid at work.
Why YSK: there has been quite a development in the first aid medicine and some things we used to learn are now regarded as myths and should be avoided. Anyway it always good to, keep your first aid knowledge up to date.
Yes, CPR is brutal and more often than not ineffective. That TV trope where someone gets a few compressions suddenly coughs and sits up all alive and healthy again is complete BS. Literally never happens.
My wife's a paramedic and in seven years has only seen someone spontaneously regain pulse after CPR twice - and that's with a team of highly trained professionals and a whole bunch of fancy equipment.
Still worth trying in many cases though, but it's certainly not a miracle procedure and not something that should automatically be done in every case.