Mark Twain, most famously known for his book 'The Adventures of Tom Sawyer' and for creating the character known as Huckleberry Finn, isn't actually Mark Twain. Mark Twain confessed the truth to an interviewer, and didn't hesitate to tell them the depressing tale from his childhood.
Mark Twain actually had a twin brother named Bill, and they looked so much alike from birth that even their own mother couldn't tell them apart. One day, the maid was giving the twin babies a bath when one of the children slipped into the depths of the tub and drowned. No one could tell which twin had drowned, and which one was still alive.
"Therein was the tragedy" said Mark Twain. "Most people thought I was the one that lived, but I wasn't. I was the one that died." The parents assumed that Bill Twain had died, and that Mark Twain had lived. In reality, Bill Twain and had lived but they THOUGHT he was Mark Twain.