Well, I am happy old fart who had to retire at 55 - far too young. So I found another job. I'm now fully retired and feel all the better for it. Like many others here, the idea of all those nights out of bed, early morning calls and multiple time zone changes at age 65, let alone 75, would fill me with horror.
I was lucky and have good pension, but feel it is much better to enjoy a quiet life after 60........or perhaps 65 at a pinch.