Right, so let me try to explain how its done! (ignore the perspective issues, each square is the same size.
First of all you need to sew your squares together as follows, (ignore the letters on the photo for the moment!)
So with your 22 squares you need to start with 2 squares turned diagonally, then 3 squares, then 2 squares, and so on till they're all used up.
Now comes the complicated (to explain) bit.
Fold it all in half along the x-x line, through the 2 square line.
Then you need to oversew the line joining A-A to B-B, then a-a to b-b.
Then you need to pull points B and D together and sew from there to point C. And also from b/d to c. Then also from BF to E, and bf to e.
Finally pull DF together and sew to X, and df to x.
now you should have something that looks like this:-
Now by sheer fluke you can actually see the bag from the same side as the flat version! Hopefully this will help you to see how it all goes together. Now just have to find/make some handles!