What was wrong (mentally) with this person I encountered?

When I was in boston i was picking up breakfast when this lady walked up to me. I thought she was going to ask for instructions (which I thought was a bit odd because I am only 16 and look alot younger). So I slowed down and she stopped and said, "repetition is the key, is the key, is the key, repetition is the key, is the key, is the key," in this sing song sort of voice. It seemed she had a mental problem but when I looked around there was no one around to help her like a nurse or something. What was wrong with this lady and will she be ok on her own?