I've been wondering when did our standard matzah - i.e cardboard crispy - originate? as most of us know, the Haggadah mentions that Hillel used to "wrap" - with his matzah - implying that at least at some point in the second temple, the matzah was soft. So just when did the Matzah become so hard? I was somewhat surprised to learn, that it is modern technology that we have to blame, rather than some crazy rabbis in Volozhyn.
According to this source I found online, the problem of "Hard" matzah, started when Matzot were mass produced. Since they had to make the matzah ahead of Pesach (so they won't risk having Hametz) - and they had no way of keeping the soft matzah fresh, they started making the cardboard like dry matzah. The dry stale matzah, we all know and love, can keep for many days - and hence was perfect for mass production.
Note: I'm slightly limited in my book library at the moment, so I've not been able to find any of the sources quoted..