Never under-estimate anybody and never over-estimate anybody.
Simple people are often able to give good advice to those who are considered intellectually superior.
In English, the proverb was first recorded in this form in 1641, but the sentiment it expresses is found in the romance Ywain and Gawain (c. 1350).
Dutch
Een gek zegt wel eens een wijs woord.
French
Le fous inventent les modes, et les sages les suivent.
Un fol einsegne bien un sage.
German
Ein Weiser kann von einem Narren lernen.
Italian
Anche il pazzo dice talvolta parole da savio.
Latin
Interdum stultus bene loquitur.
Portuguese
Do néscio as vezes bom conselho.
Romanian
Să-ți aduci aminte de cuvintele nebunului.
Cel înțelept de la cel nebun multe află și învață.
Scots
A fule may gie a wise man counsel.
Spanish
Del hombre necio a veces buen consejo.