There's an old story in Venice of a famous biscotti which the Venetians perfected. It was nutritious, would last for years (handy for those long voyages at sea)

There's an old story in Venice of a famous biscotti which the Venetians perfected. It was nutritious, would last for years (handy for those long voyages at sea) and was reputedly very tasty. The recipe was jealously guarded by a single baker who would pass it on just before his death. In this manner Venice became famous for this particular biscuit. Unfortunately the last baker to be entrusted with this knowledge whilst walking down the street had something drop on his head. The recipe died with him. Many, many years later the Ventians were under siege by Napoleonic forces. There was a fort holding out for days. Eventually rations ran out. As luck would have it the soldiers at the fort discovered a stash of this famous biscotti in one of the store rooms. They were still edible. I don't know how much of the above is true, I recall hearing the stories in Francesco Di Mosto's wonderful Venice series (highly recommended) but it does remind me how precious and fragile knowledge is and how easily it can be lost.