Supposing there are some other people somewhere, people we don’t know?

Once she had said to him, ‘Supposing there are some other people somewhere, people we don’t know?’
He had looked at her seriously.
‘What sort of people?’
‘Perfectly charming people. Really delightful, intelligent, amusing, civilized…And we don’t know them, and nobody we know knows them. And they don’t know us and they don’t know anybody we know.’
Bob had thought for a moment and then he had said, ‘It’s impossible. But if it were not impossible, then I don’t think I should want to know such people. I don’t think I should find anything in common with them.’ 

I. Colegate, The shooting party (1980), 120