For instance, if a character talks about horse riding, one needs to know something about horse riding as an actor, otherwise one will be faking. More importantly, one must study the values of different people to understand what situations would have meant to people, when those situations might mean nothing in the actor's own culture. Without this work, Adler said that an actor walks onto the stage "naked". This approach is one for which both Marlon Brando and Robert De Niro became famous.