Proust pour tous: jouer son rôle du mieux possible; play your part the best you can

D'ailleurs Odette trompait M. de Guermantes, et aussi le soignait, sans charme, sans grandeur. Elle était médiocre dans ce rôle comme dans tous les autres. Non pas que la vie ne lui en eût souvent donné de beaux, mais elle ne savait pas les jouer.

Marcel Proust Le Temps retrouvé

It must be added that Odette was unfaithful to M. de Guermantes in the same fashion that she looked after him, that is to say without charm and without dignity. She was commonplace in this role as she had been in all her others. Not that life had not frequently given her good parts; it had, but she had not known how to play them.

Time regained