Ah yes, that was me in the mid '70's to mid '80's 'til our kids started arriving !
Having had my interest renewed by my son and an old twinshock, we went to a local trial. I came back in quite a confused state, I couldn't believe how complicated the sections were with so much choice - clubman .........expert routes etc ! The riders were doing all sorts of things which did not compute, from virtually lying on the ground stationary, stopping with their feet down. Non of whom were scoring a five.
There was a lot of clever youngsters stopping and jumping/hopping with their feet up and then roaring up unbelievably slippery banks from a standstill, which was very impressive and way beyond anything I could ever have attempted in my younger days!
The easier routes looked fine for my abilities on a twinshock back in the day.
I was an expert in those simpler days and thoroughly enjoyed rubbing shoulders with the Rathmells and Lampkins at the odd national and British Championship round and riding or attempting the same sections and comparing you results with theirs, which could be quite humourous !
I watched the first video and stayed with it only for 5/6 minutes because I know that I couldn't ride such sections now or then. Whereas, I always had a belief that I could in my day. Although I would still allow stopping with feet up only, anything else must have forward movement.
My other observation is that the new style bikes seem very awkward to paddle out of a section, I have a vivid memory of seeing Martin Lampkin plowing out of a section sitting firmly on the seat of his Bultaco once he had had three dabs in a muddy section. (St David's Trial I think).