What surprised me somewhat about it, and it may just have been a feature of the different levels of decorum people had during those times, was how phlegmatic most of the commentator/veterans were, not just when referring to the fervour to enlist, but the 'matter of fact' way they just got on with things (to the point of appearing almost jolly when away from the front line) once they started to realise the full horror of the trenches...."It was just a job", "We did what needed to be done", "There was no complaining", etc etc.
My perception of the Great War had previously been influenced and jaundiced by books like the superb "Birdsong", and by my own great-grandfather's experience in the Somerset Light Infantry; joined up straight away, sent to the trenches in 1915, copped for a gas bomb on the Ypres Salient (Passchendaele) in 1917 and, as a result of his injuries, saw out the war in the Labour Corps. He then came home and got drunk almost every night, before going out in the rain looking for work and catching pneumonia and dying just 2 years after the war ended - his gas damaged lungs unable to fight off the infection. His final indignity was to be buried in an unmarked grave cos his family (wife and 5 destitute kids) couldn't afford a headstone, and to this day all anyone knows is that he's somewhere in Montacute churchyard.
The shots of the green gas rolling in toward the soldiers then had me tearing up, as did the recollections of how after demob, certain employers wouldn't take ex-soldiers on and the 'man in the street' had no conception of what the troops had been through. I can remember my grandad, who was 17 when my great grandfather died, telling me when I was a kid that his mother would berate his dad all the time about being a "lazy, drunken, good for nothing", when the poor bastard clearly had what we would all recognise today as PTSD and had been a real grafter before the war started.
Heart-breaking stuff and a wonderful job by Peter Jackson