In high school, my very best friend had parents that were retired, around 70 years old as I recall. While they were very doting parents, the age gap was just so wide that it was difficult for them to support my friend in all of the ways that she needed them.
I too feel that 66 is relatively young and, quite frankly, every year I live I raise the bar for what is considered a senior citizen in my own mind. Funny how things like that go.