One of the benefits of being a designer is the regular
opportunity to find one self to be wrong. 
It is humbling and good for the soul. 

I was blessed with such an opportunity a couple of days ago
when I swatched up the box pleat for the Joyful Ferocity and realized that I
had planned only enough stitches for a single fold (like a book) and would not
have enough stitches for the return fold (unless you have made box pleats,
either sewing or knitting, this will probably not make much sense without
diagrams– but trust me, it was wrong).

So, puzzle, puzzle, puzzle through the arithmetic.

Then, last night, I was working on the bonnet (to go with
the matinee jacket) and got to the end of the first pattern row only to find
that something was amiss.  Surely, the
designer had not intended it to have half a scallop on the left edge – but I
had run out of stitches!

Now, when I something comes up amiss, I do not automatically
assume errata.  I painstakingly exhaust
all other possibilities:  my own
mis-counting, mis-reading, mis-understanding. 
Lots of counting and arithmetic goes on. 
But in this case, I simply did not see how I could make it work using
the number of stitches I had been directed to cast on. 

So, I sifted through the pattern instructions looking for
the smallest possible amendment that would set everything right.   (this is like the scene in the movie where
the bomb-defusing hero has to decide whether to clip the red wire or the blue
wire)  The instructions said to keep 3
sts at the beginning and end of each pattern row in stockinette.  What if I changed that to 2 sts?  Shazam! 
Suddenly, all the numbers worked! (like the scene where the computer guy
hacks into the main frame and all the gobbledy-gook on the screen melts into
lists of CIA operatives)  Yes!