Alzheimer's, the most common form of dementia as we age, affects more than 5 percent of the population over the age of 65. The good news is that recent studies indicate that education and regular mental stimulation can reduce the incidence of the disease and/or delay the onset. Adopting an intellectually stimulating lifestyle can benefit aging individuals beyond just learning something new - it can keep them learning and living independently for much longer. (as quoted in SRES July/Aug/14)
As we age, downsizing and decluttering can help us keep living independently as opposed to adopting the generic retirement lifestyle options most currently promoted.