Well I Used to work off ladders up the three story's high rigging telly aerials when younger, and I thought I'd survived the odd slip off a roof ladder rather well sliding down a slippery slate roof etc, and had to use a pair of cutters to "stab" the roof to make a hand held brake;!..
But last year a simple fall of a latter up a power pole from 8 metres saw me in hospital for a month in a coma and not expected to make it:(
However despite the skull fractures and hematoma's, subarachnoid haemorrhage, a fractured femur which came right through the skin and a lacerated elbow we're back at work not that much worse for wear 'tho a bit more risk adverse than before;)..
However one thing that will be good advice to all concerned on here and elsewhere is if anyone has had much of a bump on the head even if they appear OK afterwards, is -- STRONGLY-- advised to go to the accident and emergency unit of a hospital to have it looked at. Even minor head injury can cause internal bleeding which can have devastating consequences if left untreated!....