Why did people start farming instead of hunting?

For most of human history — we're talking hundreds of thousands of years — people were constantly on the move. They followed herds of animals, picked berries when they ripened, fished rivers, and set up camp wherever dinner happened to be that week. No houses, no farms, just wandering and hunting and gathering whatever nature offered. Then, about 12,000 years ago, something wild happened: people stopped moving and started planting seeds on purpose.
Here's the thing nobody tells you: farming was harder than hunting and gathering, at least at first. You had to clear land, plant seeds, pull weeds, watch for pests, and wait months before you got anything to eat. Hunter-gatherers worked maybe four hours a day and ate a huge variety of foods. Early farmers worked from sunrise to sunset and mostly ate grain. So why switch?
