Only if you're old. It was a negative predictor in the young group:

Personality predictors of cognitive abilities differed among the three groups studied. Openness and extraversion were important predictors of general knowledge in young adults, presumably the time of life when general knowledge increases fastest, with those higher in openness and lower in extraversion scoring higher on general knowledge. Openness was found to be a strong predictor of young adults' ability to retain general knowledge and store short-term information.

(emphasis added)