Makes sense. My grandpa is one year his junior and you would never see him react too strongly to anything, even though grandma (also still alive) always had an, ahem, fiery personality.

Also he refuses to sit and moves around all the time, venturing outside every day from their apartment four floors above ground without a lift.

Interestingly his own father didn't make it to his 60s, so there's certainly a lifestyle component to this.