Rice farming required FIVE TIMES more labour in Ancient China vs Wheat farming in Europe. Europeans easily had more than twice the amount of free time per capita, and yet it took THOUSANDS of years for them to surpass China in terms of culture and technology. And once China got a tractor and moved his twice-as-strong work ethic to studying, he took over Europe literally within a few decades. Like literally- Father China took out his belt and is whipping his little son Europe right now. He would have done so much earlier but he was busy farming rice.