«Headache» © by Pedro VeraAt the core of David Allen's Getting Things Done (GTD), you'll find the statement that you should get all of your commitments out of your head and into a reliable system because your head is not a reliable system.

There are numerous myths about memory, like one can keep 7 +/- 2 things in the short-term memory; memory uses images; or: linking with bizarre images is best for memory. They're simply not true and may give you an unjustified feeling of security. Why?

Here are 3 reasons why your «mental RAM» isn't a reliable GTD system:

1. Emotions impair your memory
   While connecting information to emotions is a technique for memorizing something that is recommended everywhere, this usage of emotions has its downsides, as described in Wikipedia:
   The mood congruence effect means information becomes the stickier the more it incites a mood similar to that you're currently in; additionally, being in a negative mood fosters remembering mostly negative information, too. Should you try to be positive, then? No - to make things worse, there is a Catch-22: trying to be brave and positive in a sad situation may also impede your memory.  » Read more