Memory is crucial to our lives because it allows us to apply our past experiences to our present lives. Memory allows us to function normally. Without memory we wouldn't know what to do when we got up in the morning or recognize the faces of those we love. It is normal not to remember every detail of our lives, but sometimes people begin forgetting too much. This is a disease and it is called Alzheimer's.

Alzheimer's disease is a form of dementia that gets worse over time and affects memory, thinking, and behavior. Alzheimer's accounts for 50 to 60 percent of the cases of dementia, and it occurs at alarming rates as people age. For those people aged 65 and older the risk for the disease is 13 percent, but once you hit age 85 and older the percent jumps up to 42 percent. Alzheimer's begins with the forgetting of newer memories, and ends with older memories being the last to go.

When you have Alzheimer's the brain contains many senile plaques and neurofibrillary tangles that contribute to the loss of synapses, and death of cells in the hippocampus and cerebral cortex. It is not known what exactly causes Alzheimer's but it is thought to be partially genetic and partially environment and lifestyle based. For example, it has been shown that being physically active reduces your risk for Alzheimer's.
The disease of Alzheimer's is close to my heart because my grandfather had it. I personally experienced his decline and memory. He had to be moved from his house and to a nursing home because he could no longer take care of himself. I wonder if scientists will ever discover the exact cause of Alzheimer's and if there will be a treatment that works. What would our world be like if people no longer had memory loss? Would it increase life span? Would it be a good thing or a bad thing? I guess we will just have to give Alzheimer's research time and wait to see the outcome.
Sources:
http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001767/
Psychology Textbook
