This lady's 83 year old mother has Alzheimer's disease which is a killer of the brain, of their personality and well being; and these Alzheimer's patients are very forgetful and disoriented. They may be physically healthy but mentally in another world and may not understand the simplest things you say. Mental illness is a biological brain disease. Symptoms may change over time, family relationships may be in disarray and behavior may be unusual. In an Alzheimer patients's brain, thoughts stop and don't connect properly. They may experience delusions and disorientation. Learn to be sensitive to the logic behind the disorientation of very old people. You will probably need help in caring for an Alzheimer's patient and they may need assisted living facilities. Many of the newer facilities have good security.