Everybody living has been 'trained' John. By their parents when young, by their schoolmates as they got older.
If u r doing a riskier activity later in life like caving or climbing you need training of some sort, even if just off your more experienced mates. Like I said above I know of someone who almost free-fell down Slit Pot. It is so easy to forget to check something, you should know that as u r one of the most experienced cave divers in the country. Everything has to be checked and double checked, unfortunately less experienced people don't always do that, which could be why we've lost some of the most respected cave divers in the past, oh I don't know, 20 or more years?
I taught my friends in my caving club SRT & ladder work. The only reason one of them is still with us is cos I instilled (trained) in them to always clip in to the next section of rope when ascending. He almost slipped down a 50ft pitch, but didn't thanks to having his cowstails clipped in. Life is a constant training exercise!
What if you didn't arrest a friend who fell while climbing on a crag? You have to know how to belay and lifeline. Training. Someone had to show you how to do it safely & properly, then practice.
You absolutely do need insurance these days. What if I did 'something' in my area of the peak that caused a child to fall off their bike? Their parents would sue me for negligence. These are important issues.
So just get ya insurance and use best practices in whatever u r doing and u should be fine. Cave/Climb/Dive/Cycle/Extreme Iron (lol) safe everyone.