|Putting the psycho in|
|Men who stare at goats|
|By the powers of tinfoil|
Intuition is the mystical power that psychics, women, and cats have that gives them the ability to divine useful knowledge about a variety of subjects without using rational or scientific means. The explanation for the source of this supposed power usually springs from a God of the gaps type argument. Science can't explain it, therefore intuition did it. Psychology offers up some caveats: the unconscious can contain underlying thoughts and memories which can surface to the conscious mind, but that is not inherently the definition of intuition, because the concept of the unconscious is within the realm of science.
Scientific testing has shown time and time again that psychics under controlled conditions never perform better than wild guessing. Intuition is inherently fallible, often what seems intuitively correct is simply wrong. Intuitions and first-impressions do not perform better than empirical research and proper scientific analysis unless you can prove otherwise. Cats have been shown to exhibit freakishly high levels of intuition; however, their communication is limited to meowing and urinating, so non-cat scientists remain baffled.
 Confirmation bias
When you want to believe that something is true, you will go out of your way to find confirmatory evidence in favor of that particular belief while blocking out other lines of evidence or competing contradictory explanations. When you make a guess and that guess turns out later to be true, someone who believed in intuition would blurt out "My intuition told me so!" while blocking out the other, more simplistic, possible explanation: that they had simply guessed correctly.