The enduring disorder in memory retention is known as Alzheimer's disease. Generally, the disease affects the brain tissues after one reaches forty years. Once affected, Alzheimer's gradually destroys the ability to reason, remember, imagine and learn. It is marked by abnormal clumps (plaques) and irregular knots (neurofibrillary tangles) of brain cells. For reasons not well understood, these plaques and tangles take over healthy brain tissues, devastating the areas of the brain associated with intellectual function.

"Alzheimer's can be called the long good-bye. You grieve about the loved one from the moment you begin to observe the gradual loss of memory and the speech and personality changes, because they are incurable. The person you love is gradually changing before your eyes. You say good-bye many times until the final good-bye at death." - Norma Wylie, 1996