A few "famous quotations":
Mark Twain: "It's not what we don't know that hurts us; - it's that we
know so much that ain't true."
"It's not what we don't know that hurts us,
it's what we know for sure that just ain't so."
O Mark Twain
"It is not what we don't know that is the problem,
it is what we know that is wrong that gets us in trouble.
-Samuel Clemens (aka Mark Twain)
"It isn't what we don't know that gives us trouble, it's what we know
that ain't so." -- attributed to Will Rogers (from NewsScan Daily, 18
Jan 2000). Then in NewsScan Daily, 20 Jan, we find this: "The quote
"The trouble with people is not that they don't know but that they
know so much that ain't so." actually originated not with Will Rogers
but with Josh Billings (1818-1885; his real name was Henry Wheeler
Shaw); there is a good discussion of the misattribution of this quote
in Ralph Keyes' excellent "Nice Guys Finish Seventh." (Michael Cook)"
Tom Walker