Steve,
Do I really need to "test" most 93 year olds? How would such tests be done? You just admitted yourself that you gave up your licence. Why? For fun? Or to avoid unnecessary risks? At 61 you still had a bit of wait till 93..
I have seen fairly few cases of folks much younger than 93 for whom even going to the toilet was a challenge. Never mind the details. I think I know where you're coming from - "some 29 yo t*** will not say I can't do this or that". That was not my point. My point is based on natural way things change.
Up my own arse you say.... Funny that, one elder gentleman that fainted in our local Tesco's car park didn't think so. It was just normal shopping with family, I went to pick few magazines and then my girl runs to me and shouts 'get your arse over there quick, someone just crashed into the gate'. As it turned out, he just lost it behind the wheel, floored it, smashed delivery gate and woke up after that. Brand new Mazda 6 was a total write off, by the time I arrived to the spot all possible fluids were leaking on the ground, someone took the keys off the barrel but ignition was still on. Staff was there but they didn't know what to do. After I managed to pop the hood to rip off the leads off the battery, I was holding his head and his blood was dripping on my hands till fire brigade arrived to cut him out of the wreck. Luckily he was responsive, so we managed to find out numbers to his family and some documents. Fella in his 60s. I will remember till my last day the look he gave me when he was being taken to the ambulance and the way he said 'thank you'.
Reading few post of the new forum member that I happen to be tells you nothing about my mindset. Same as your response tells me nothing about yours. Rest assured I am far from it. I've seen some nasty stuff that involved elders and young ones alike, including death. Things I didn't want to see.
But let me congratulate you on well rised children. I am a father of two myself, just a bit younger. My son started to ride bikes when he was 4yo - two years ago. He has his own bike and believe me, running after him in the car park just to catch him if things were to go pear shaped paid off. His skills are amazing and he rides like an animal - but knows his own limits. Sometimes we ride together too

.
But getting back to the point - I think you misunderstood my post a bit.
Peace!