The phrase refers to Japan's real postwar boom, when manufacturing, exports and living standards rose sharply in the decades after 1945. As a short spoken clip it circulates online detached from its lesson, reused as a deadpan label for any unlikely comeback. Creators borrow the serious tone of a history narration to make ordinary improvements sound world changing, which keeps the line useful for school edits, gaming montages and ironic transformation videos long after the original context has faded from view for most viewers today.