my own personal experience I can infer that most movie-goers mistook the strategy profile where all men go for the brunettes for the Nash equilibrium.

This is strengthend by the fact that the movie later talks about Nash challenging the dominant opion in economics that if you follow your own interest you benefit the common interest.

I must have been sleeping during that part. But think of the price-setting of oligopolies. Companies play the Prisoner's dilemma, therefore they sell at marginal cost (Bertrand model) and by doing so they benefit the public interest => If you follow your own interest you benefit the common interest. QED. ;-DD