“The greatest thing since sliced bread” is often said as a joke. Sliced bread seems mundane and obvious to us. But although the concept of sliced bread is simple, the machine that slices it is an engineering feat. Thirteen years in the making, it finally came to be used commercially in 1928. Sliced bread (obviously) was a huge hit. And the phrase “greatest thing since sliced bread” was once used as a sincere marketing catch phrase. In 1943 the government actually banned sliced bread to conserve metal for the war effort. There was such an uproar that the ban was discontinued shortly thereafter.