In 1965 (Russell = 93 years old) a young mathematician, G. Spencer Brown, pressed me to go over his work since, he said, he could find no one else who he thought could understand it. ...But as the time drew near for his arrival, I became convinced that I should be quite unable to cope with it and with his new system of notation. I was filled with dread. But when he came and I heard his explanations, I found that I could get into step again and follow his work.
Source: The Autobiography of Bertrand Russell, v.3:1944-1969 ,chap4:The Foundation,(1969)
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