confidently incorrect

Just a few words on the illusion of certainty—especially the kind that gets our undies in a wad when someone dares to disagree.  (There seems to be plenty of that in the world lately.) 
 
First, memory is not a filing cabinet; it’s a sketchpad, and it smudges.

And what are we getting so mad about, anyway? The reality of our correctness?  It is widely unappreciated in my family when, during a discussion, I ask, “What is reality?”  Recently someone responded, “we can all agree the sky is blue.” 
 
Most would agree! But here’s something to consider: the sky isn’t really blue—it’s just light putting on a show.  Sunlight hits the atmosphere, blue waves scatter more, and voilà: sky-sapphire illusion!  And here’s the tricky part—your “blue” might be my “bluish-maybe-purple.”  Not a soul can confirm if we’re seeing the same thing, though we’ve all agreed to nod politely and call it “blue.”

As Voltaire said back in the 1700s, “Doubt is not a pleasant condition, but certainty is absurd.”