It seems like I forget things alot. I guess I'm pre-occupied with other thoughts going thru my brain. ... Does anyone else do this?
Mainly people who are pre-occupied with other thoughts. For whatever reason. Totally normal.
Take notes. Even if you don't read them again the act of writing them down will often lock them in your memory. And it would be a good habit to get in because as you get older you will normally forget more and having the habit of writing it down will make things easier later in life.
And as far as the thoughts that you are focused on it also is a good idea to write them down. It helps to clarify issues. On some stuff when it is written down then your brain can release them for the time being and allow you to handle the other stuff that is being pushed aside. Or it allows your brain to take a break and relax.