I guess everybody, even the smartest people who ever lived, have days when they feel dumb — really, really dumb. Oct. 1, 1861, was that kind of day for Charles Darwin.
In a letter to his friend Charles Lyell, Darwin says, "I am very poorly today," and then — and I want you to see this exactly as he wrote it, so you know this isn't a fake; it comes from the library of the American Philosophical Society, courtesy of their librarian Charles Greifenstein. Can you read it?
Whoah! You know the feeling, right?