Designers/Architects can benefit by learning more about how people process, learn, remember information and understanding internal mental states.
Because Cognitive Psychology is all about internal mental states and process, where the user get bored, perception etc.
One simple answer to the question of "How valuable is studying cognitive psychology for UX,HCI?" is that there is already
agreement about the importance of both topics to
computer science education in general.  For example,
the report of the ACM/IEEE-CS Joint Curriculum Task
Force [2] clearly identifies human-computer
communication as one of the nine core areas of
computer science.  In this core topic the report authors
include both computer graphics and human-computer
interaction as related topics.  Furthermore, the authors
of the report point out that cognitive psychology is an
important supporting discipline for three of the nine
core areas of computer science, including artificial
intelligence and human-computer communication.

Human-Computer Interaction and Cognitive Psychology in Visualization
Education.

How valuable is studying cognitive psychology for UX?
I have just started using QGIS. I've loaded the "openlayers" plugin and added a google hybrid layer, which is based off the WGS84 datum to my understanding. Now I create a shapefile and add a new line vector layer based on the same datum. I draw a line and then zoom out. Now, the line has moved with regards to the google map (i'm drawing a road and now the road no longer lines up with the original road I'm using for a guide). 

My end goal is to make a georeferenced shapefile with some roads. Is my methodology flawed or is their a problem with my plugin (assuming the former of course!)? 
