Our brain is a big prediction machine.  It gathers and collects data and observations and it applies them into relative "buckets".  Some things get ignored, somethings get misfiled, but everything gets categorized.

 

Sometimes thats good-- It makes conclusions faster.  Sometimes its bad-- It forms false conclusions.

 

The secret to life and creativity?  Know what categories you are putting things in, know why you are putting them there and most importantly, recheck those assumptions OFTEN.