"Sensible people learn from their mistakes."
Translation:Verstandige mensen leren van hun fouten.
Although the dictionary suggests otherwise, verstandig and redelijk are not really synonyms. “Verstandige mensen” refers to intelligent people whereas “redelijke mensen” would refer to people who are open for other people’s arguments or that are fair. For example, in a conflict situation, one could say: “Het zijn verstandige mensen, maar nu zijn ze helemaal niet redelijk” , which would translate as “They are intelligent people, but now they are not being reasonible at all.”
Hope this explains the difference, Frederic, native speaker