Also, we joined Saga when I was 50, and we get the Saga magazine.
Every month they list famous people who have milestone birthdays (50, 60,70,80 etc) and there are many people over 60 and 70 who lead very active and interesting lives.
Tell him David Bowie is 63, Paul McCartney is 68, Jane Fonda is 72, Judi Dench is 75 and so on.
There is plenty more he can do when he is 60.
Suggest he tries something "new". Walk the great wall of china for charity, write a book, visit Chile, build a web site etc etc etc.