Return home, my daughters; I am too old to have another husband.

I hope I can do it before I'm too old.

That's remarkable in its own right, but the real "population explosion" has been among the oldest of the old - the centenarians.

This isn't just good news for the oldest old and for society in general; it also provides clues about how more of us might achieve a long and healthy old age.

Not all of the oldest old survive by delaying illness or disability, though - many soldier through it.