Between the two extremes of educated Greeks and Asia Minor geeks, may I suggest that there were at least two other groups of people that had an inkling of a round earth.
Sailors / fishermen
The horizon at sea level is about 15 miles. You don't have to go very far before other fishing boats from the village start to disappear over the horizon. Even if the village is still in sight, your neighbor's boat will "sink" from view except for the mast. A curved surface will give that illusion and ancient mariners knew that, even if they couldn't write about it. Even if you followed the coast line, your starting point would sink from view, the farther you sailed.
Camel Jockeys on caravans
The horizon at "sand" level is also about 15 miles. The caravan routes around the Middle East had been established over many eons. Especially when traversing the Sinai desert, one could be out of sight of landmarks for many hours or days. But the illusions the travelers encountered were the same as sailors. Topographical features slowly rose out of the desert in front of the caravan and receded behind it.
But then, there's no Book of Bedouin in the Old Testament now, is there? No one asked them what shape they thought the earth was.
(:raig
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