"Let Your Fingers Do the . . . Proofreading?"

Have you made a mistake typing: your fingers know

My own experience shows this to be valid.  Before I look up  from the book I'm typing from to check the screen, I know whether or not I've been successful (or mostly successful).  I can tell by the tangle in my fingers whether it is a heavy-proofing or a light-proofing day.  And as most of you are aware by now, I write so rapidly so early in the day that it is entirely probable that everything looks like it has never been proofed.  (Most true).