I feel that a person is as old as the number of generation that succeeds him when he is alive.
My father, though at 84, was not considered old as he still had a daughter living with him and a 11 year old grand son hanging around him. But people of his age had his children married who in turn had their daughters/sons in law and they had children of marriageable age. So, they become great great grand parents and the relationship they share with the younger generation is not as strong and the loneliness creeps in, despite the fact they might stay in as single family.
I would love to be contradicted and this is meerly an experience I felt when looking at people of his age.