If scientists really knew the answer to that question, we might have already developed a "cure" for memory loss. Wouldn't that be nice! As with most questions about how the brain works, scientists don't really know the answer.

Most people will become more forgetful as they get older. The increase in forgetfulness with age is often called "senility", and you may have already heard people complain or even joke that they are getting "senile".

Basically, there are two forms of memory: short term memory and long term memory. Short term memory helps you remember where you put your shoes, your address and phone number, or the homework you have to do before you go to bed. This is the type of memory that suffers most when we get older. Unfortunately, this is also the type of memory that we depend on most in our daily lives. The other form of memory is long term memory. This helps you remember the name of every pet you've ever owned, how to tie your shoes, or that 2 times 2 equals 4.

Eventually, some of your short term memories will become long term memories, although scientists don't really know how or why. Repetition is one way to ensure that your short term memories becomes long term memories, which is why you have to "memorize" your times tables by saying them over and over and over, or practice your scales on the piano every night.

Often, older people will have poor short term memories but very good long term memories. For example, my Mom often forgets where she put her scissors or what to buy at the grocery store but can tell stories about what it was like to live in London during World War II. Though my grandmother would sometimes forget my name, she could remember surviving the big earthquake in San Francisco in 1906.

According to some studies, about half of the memory loss that occurs by the age of 60 is due to genes (passed on to you by your mom and dad) and the other half is up to the person. This means that there are some things you can do to keep your memory from getting worse as you get older. One way is to use your brain a lot. It seems silly, but I've noticed that my Dad is becoming more forgetful now that he's retired. So staying active, meeting new people, reading and learning about new things every day will actually help you remember more.

Unfortunately, some people suffer from diseases that make them lose their memories faster than other people. Such people often need special care, and they rarely get better. One of these diseases is called Alzheimer's disease. Doctors and researchers hope that by studying Alzheimer's, we may learn clues about how to prevent memory loss.