Three old ladies were discussing the problems of getting older.One said, "Sometimes I catch myself with a jar of mayonniaise in my hand, in front of the refrigerator, and can't remember whether I need to put it away, or start making a sandwich."The second lady chimed in "Yes, sometimes I find myself standing on the stairs and can't remember whether I was on my way up or on my way down."The third responded, "Well, I'm glad I don't have that problem;knock on wood."As she rapped her knuckles on the table...she said, "That must be the door, I'll get it."