In our society, people are slowly squeezed out of the limelight as they age. When people reach retirement age, there is no social niche for them to move into that keeps them in the mainstream culture. They are told to go off and have a nice time. Men in particular feel this loss when a major part of how they define themselves is taken away from them at retirement. We have no labels and give no social status to the retirement years.
People simply lose their role in society.
In addition, the loss of a spouse or mate also adds to the separation of older people from the community. A person's friends drop away when that person is no longer able to participate in couples activities. The single person is forced to find new friends to socialize with at an age when making new friends is harder. All of this can lead to depression, which in turn makes it harder for a person to develop a life that is rewarding and meaningful. Keeping busy may make you feel like your life is full, but it certainly is not much fun.