The famous 19th century writer Mark Twain was a sharp fellow. He composed a lot of clever adages, and amongst them was the following:

 
"It's not what you don't know that will hurt you. It's what you do know that just ain't so."
 
This group is a resource in which we should catalog the common soundbites, claims, and "facts" that aren't facts. Round 'em up and let's tear the veils off them. Let's get down to the truth and find out what's fact and what's fiction!