Lately i have been feeling extremely forgetful. This is particularly unusual for me because I have a great memory. I can't remember words and I can't remember certain days. For example, once I forgot what I had done over the weekend...and it was only Monday! And to clarify, I don't drink or do drugs so it wasn't like there was a reason for the forgetfulness. Also I feel just generally foggy and confused often. What causes forgetfulness and what are some ways to prevent it?

Also...I'm not old, so it's not an aging thing.