This joke:
Three older women were discussing the problems that come from getting older. One said, “Sometimes I catch myself with a jar of mayonnaise in my hand in front of the refrigerator and cannot remember whether I need to put it away, or start making a sandwich.”The second woman chimed in, “Yes, sometimes I find myself on the landing of the stairs and cannot remember whether I was on my way up or on my way down.”The third one responded, “Well, I am glad I do not have that problem; knock on wood.” As she rapped her knuckles on the table, she told them, “That must be the door. I will get it!”