White-haired characters are archetypal figures of wisdom in most cases. This includes most major theorists' and cultural imagery. It is one of the few dream symbols that seems universal.
A 42-year-old woman reports dreaming: Three old women enter my room to tell me Methuselah (a legendary, 969-year-old man of great wisdom) is coming to see me. I am interested, but fall asleep. They wake me later and scold me, telling me I missed him. I am crushed, because I've always been fascinated with Methuselah.
In this dream, the old women have particular knowledge about an ancient, wise figure that they offer to share. However, the dreamer does not fulfill her obligation to the knowledge that was offered to her, and so it went unreceived. She felt responsible for missing the chance to gain wisdom by giving in to laziness.