Try doing this mental exercise over a 4 week period and you should notice an improvement in your short and long term memory.
When you are ready to go to sleep, go over what you did that day from the time you got up until you get into bed. Start with the time you awoke, got out of bed, follow your entire day step by step until the time you went back to bed. Try to recall as much detail as possible, visualizing in your mind each and every step from beginning to end. In the beginning, you probably wont remember much detail, and you’ll probably move rapidly from task to task or think of the day in large periods of time. However, try to slow down and remember as much as you can to take in as much detail as you can. With time and practice, you will notice significant improvement in your recall of events and details throughout the day.