Ask me what happened in the hardest / scariest moments of my life, and I guarantee it won't fit exactly with what others who were there remember (unless it's a well known story where we've all misremembered it together).
As for heavy load carrying, the worst thing I ever did was a Thomas bin full of mortar spares strapped to a SAS bergan frame for a joke (that I wasn't in on) which I carried up a hill on Salisbury Plain that rivalled Everest (which strangely I've never seen since). At thirty years' perspective I reckon over 100lbs, plus CEFO.
About a mile or so I carried that, and I was utterly chinstrapped.
Sounds about right, as I said I never saw it again, but it seemed very impressive at the time. Just a mile for me with that fcuking Thomas bin. That was enough tbh.
My sense of humour failure would have been very impressive if I'd had any energy at all left, instead it consisted of me on all fours next to the Thomas bin, panting "Cnuts", to the two twats laughing at me. Revenge was taken in the form of skiffed brews later in the Ex.