I think the notion of a mandatory retirement age is quite odd, I have known pilots in the airlines and the military, who should have given it up years before they were anywhere near 60 and also several who are well past that age who are physically and medically fit and who can still show the younger guys a thing or two.
If you dig deep enough you'll find that the original impetus for the "Age 60 rule" came about when an airline CEO was trying to get rid of a troublesome pilot who was approaching age 60. Said CEO had friends high up in the relevant regulator and the rule was invented and somewhat fictitious phyiological conditions promoted to justify it.
Regards,
BH.