Hamming, on how anyone can make a mistake: "I did not [discover] the FFT, though a book I had already published (1961) shows I knew all the facts necessa

Hamming, on how anyone can make a mistake: "I did not [discover] the FFT, though a book I had already published (1961) shows I knew all the facts necessary, and could have done it easily! [...] Think of my error! How much more stupid can anyone be?"