The original attribution is not W.E.B. Du Bois as he was born February 23, 1868. The 1857 book "A polyglot of foreign proverbs : comprising French, Italian, Ge

The original attribution is not W.E.B. Du Bois as he was born February 23, 1868. The 1857 book "A polyglot of foreign proverbs : comprising French, Italian, German, Dutch, Spanish, Portuguese, and Danish, with English translations and a general index" has that quote in the index, on page 413 at https://archive.org/details/b24867664/page/412/mode/2up?q=%22A+man+does+not+look+behind+the+door%22 https://archive.org/details/b24867664/page/412/mode/2up?q=%2... . On page 354 you can see it's described as a Danish proverb, https://archive.org/details/b24867664/page/354/mode/2up?q=door https://archive.org/details/b24867664/page/354/mode/2up?q=do... : "Den leder ikke gierne bag Dören, som ei selv har staaet der. A man does not look behind the door unless he has stood there himself" That phrase is indeed in the 1850 book "Danske Ordsprog, Tankesprog og Riimsprog", p153, #2385 at https://archive.org/details/danskeordsprogt00copegoog/page/n221/mode/2up https://archive.org/details/danskeordsprogt00copegoog/page/n... . FWIW, the 1897 book "Men in epigram" attributes that quote to Henri Du Bois.