Short answer: I'm no child any more.
Every time someone claims that the contemporaries of Columbus thought the earth was flat, there are other people who point out that "everyone" or "all educated people" have known that the earth was round at least since antiquity. Surely nobody could have been stupid enough to believe that the earth was flat?
Well, I did, once up on a time.
I remember being a child, asking myself if the surface of the earth had a limit. I may have been four years old. Perhaps three or five. I remember picturing someone walking in a forest, further and further away. "Can he walk forever?" I asked myself. "Or is there a stop somewhere?" I had not heard of any stop, so I assumed there was none, but could people really walk for ever on this flat surface?
Some of you may think that I must have been precocious to have such interesting questions. I wasn't. I was dumb (already at that time).
I remember having those thoughts when I was standing next to the terrestrial globe of my grandfather. I made no connection at all. I could have said to myself: "there cannot be any limit, because the earth is round", but I didn't.
And if I have been stupid, I assume that other people have been stupid in similar ways. It would not surprise me at all, if large numbers of people in the olden days believed the earth was flat, in spite of enlightened people like Aristotle, Eratosthenes, Ptolemy, Aryabhata and many, many others.
