The Flying game is a very strange place.Some can cope just topping up the Alc% level well into their 80s!Others from the same era,who never drank much,and played squash and or Rugby,left passed away in their 50s.You just cant put a number on it,but todays glass cockpit flying offices,are equivalent to several mobile phones strapped to your head for hours on end!!You can never forget,no matter how the CAA view it,that there are noxious,not to say poisonous,fumes emanating from bleed air pressurising and air/con the cabin/cockpit.I lose many friends/colleagues every year from different forms of the dreadful disease well before they should.Most of the older generation could adjust to differing cicadian rhythms in sleep patterns,from day/night and back,but not for long.Long nights can be killers,then driving home especially after a prolonged roster period.Nevertheless I would not have missed it for the world,but would have second thoughts flying todays machines!!!