Short-Term Memory Loss

If you think of your brain as a storage system, the 'small' room where you keep things handy is where short term memory, known as STM, resides. You may also hear the term “working memory” used when reference is made to STM. That's because the information stored in short term memory is what you need to get “working” on immediate tasks. When a clerk gets a $5 bill and needs to make change,

the fact that $5 and not some other amount was handed over is stored in STM as “working” memory. When you discuss the movie you just saw after leaving the theater, that would be use of STM.
The average person is able to store material in STM at a rate of 7 ( ±2 ). That means that most people will remember about 7 individual 'bits' of information at any given time. So, if you are read a list of 10 numbers, you'll probably immediately be able to recall about 7 of them. If you're able to 'bit' information, i.e., combine them, that would count as a 'bit' towards the magic “7”. that's why numbers such as zip codes or area codes are remembered easily as a single 'bit', even though they contain several numbers.
When memory problems surface, it is usually first felt in one's short term memory.