No one really knows how many different faces someone can recall, for example, but various estimates tend to hover in the thousands—based on the number of acquaintances a person might have.

例如，没有人真正知道一个人能回忆起多少张不同的面孔，但各种各样的估计往往会在1000个左右徘徊——基于一个人可能认识的熟人数量。