What is your thought process if you get to your elderly parent’s home and there is a sock on the doorknob?

There could be a few different reasons why there is a sock on the doorknob. Maybe the person who lives there put it there as a way to indicate that they don’t want to be disturbed. Or, it could be a sign that something is wrong and they need help. If I was concerned about my elderly parent, I would try to find out what the meaning of the sock on the door was before taking any further action.