The conscious mind can only hold 7 plus or minus 2 bits of information a second. That's why few people memorise phone numbers longer than 9 digits.
So if you're activating you have your mind probing question and purpose, and you find answers an part there of. You cannot hold any more until you put some down.
It's just like you cannot remember the first sentence of this post if you're currently reading this one. Any more than I now remember what I wrote because I need my conscious mind to focus in the next 5 to 9 words I intend to write. If I'm still remembering the previous set of works I cannot write or focus on the next set. It's the natural working of the mind.
That's why if you don't do something to serve as a reminder, you've forgotten you need to by the milk as soon as you picked up your keys and walked out the door. So you anchor the memory to your keys then you can allow yourself to forget because now you have a reminder, trigger or memory peg for buying the milk.
That's why mind mapping is so useful. If you don't do something to anchor your intention to remember. You will forget and forget faster than you'd like to believe.
Alex
