Safety thanks to cardboard?

I am a fan of cardboard: from my early years I made many things out of it since it was cheap, easy to get and easy to work with: no fancy glues or exotic tools are needed,  I even managed some pretty spectacular results getting it to bend. See below.

Now someone has made a real bicycle helmet using cardboard cells to absorb impacts.

Here is the WIRED page.  Some people can't quite believe that something resembling corrugated cardboard can be a good impact absorber.  On the other hand, how come it is such a puzzle? Much of the world's delivery goods arrive in boxes made of corrugated cardboard , and for good reason.

The stuff the helmet is made from resembles the inside of modern doors: hexagonal cell sheet, an idea also used in aerospace although they make theirs from metal or modern composite.

I am impressed  and pleased by the gent concerned, and to top it all off the Kranium company are offering helmets shaped to your head, (they scan your cranium!)  which would be a  great safety improvement. Not sure I can afford a custom helmet but at least the potential is there. 
Kranium also make a pretty good electric bike too, seen here.