He didn't invent them out of the blue, though. Here's the story:
* He was a carpenter: Christiansen was a skilled woodworker who owned a small workshop in Billund, Denmark.
* The Great Depression: In the 1930s, the Great Depression hit Denmark hard, and Christiansen's business suffered.
* Finding new ways to make money: He started making wooden toys to supplement his income.
* The inspiration for LEGO: He noticed children were drawn to interlocking wooden building blocks, which were popular at the time.
* Developing the LEGO brick: He decided to develop his own version of these blocks, making them more durable and easier to connect.
* The name "LEGO": In 1934, Christiansen officially named his company "LEGO," a combination of the Danish words "leg" (play) and "godt" (good), meaning "play well."
So, LEGO bricks weren't a sudden invention, but rather a combination of Ole Kirk Christiansen's carpentry skills, his entrepreneurial spirit, and his observation of what children loved. He saw an opportunity to create a toy that would be both fun and educational, and his innovative idea ultimately led to the global success of LEGO.