That photo above used to be one of the most valuable commodities in the world.
Land.
Most people used to work in agriculture; growing and harvesting crops. This type of physical labor was the main source of employment less than a hundred years ago.
Soon after World War II, things began to change. Quite suddenly we moved to a “Knowledge Society”. Then all of a sudden people were being paid to sit down to use their mind instead of their physical strength.
It is odd to think, that nowadays your knowledge is considered far more rare and valuable than acres and acres of land.