Poulenc turned to opera only in the latter half of his career. Having achieved fame by his early twenties, he was in his forties before attempting his first opera. He attributed this to the need for maturity before tackling the subjects he chose to set. In 1958 he told an interviewer, "When I was 24 I was able to write "Les biches" it is obvious that unless a composer of 30 has the genius of a Mozart or the precociousness of Schubert he couldn't write "The Carmelites" – the problems are too profound." In Sams's view, all three of Poulenc's operas display a depth of feeling far distant from "the cynical stylist of the 1920s": "Les Mamelles de Tirésias" (1947), despite the riotous plot, is full of nostalgia and a sense of loss. In the two avowedly serious operas, "Dialogues des Carmélites" (1957) and "La Voix humaine" (1959), in which Poulenc depicts deep human suffering, Sams sees a reflection of the composer's own struggles with depression.