By the end of the study, 180 people had Alzheimers. And those whose life-space narrowed in on their immediate home were almost twice as likely to develop the condition as those who ventured out. The homebound folks also had an increased risk of other cognitive impairments and a faster rate of cognitive decline. The research was published in the American Journal of Geriatric Psychiatry.
Perhaps an indicator of where we feel comfortable, how much unpredictability we can tolerate.