Might be interesting to know, but Miller's Law states 7 plus or minus 2. What's important is that as you get older and seemingly more forgetful, it doesn't always mean your suffering from some form of age related forgetfulness. Miller's Law suggests that the average human being's short term memory on average can only hold 7 items at one time. The plus or minus 2 is dependent on grouping .... such as if you have to remember 2-4-6 and 8 and you group it into 2468. This is what I was referring to earlier in my post. So lets us just say this rule is fact, as your short term memory remembers 7 items, at any given point you do something, and that replaces one of those 7 items in your short term memory, thus my reference to distraction.
This is why writing things down is a necessary exorcise as well as organizing our practices such at don't put it down, put it away helps us. No matter how good the practice works, there is always Murphy's which has it's own set of law's, such as finding your lost glass's on top of your head, or looking for the pen you need to wright down the stuff you want to remember.
Garry~