Mrs Huth Jackson in A Victorian Childhood says: 'Lord Arthur Russel told me, many years later, that when a small boy he was taken to Knebworth by his mother. Next morning he was in the big hall having breakfast when a strange-looking old gentleman in a shabby dressing-gown came in and walked slowly round the table staring at each of the guests in turn. He heard his mother's neighbour whisper to her, "Do not take any notice, he thinks he is invisible." It was Lord Lytton himself.'
(Virginia Woolf, Flush)