Some of the following posts were split from this point in another thread.
You are making a mistake by assuming our ancestors were just gullible yokels who believed whatever was fed to them, unable to differentiate between a superhero tale and an actual person. That would be like you believing everything you read in a book designed to fill up a few hundred pages which is based on nothing more than assumption and personal opinion with no factual information.
A vast portion of people believe without question that humans only use 5-10% of their brains. A vast portion of people believe without question that ostriches bury their heads in sand. Neither of these are factual and yet everyone believes them to be absolute truth. People
now are "gullible yokels", nevermind thousand of years ago.
People still throw salt over their shoulder, salute magpies, hang horseshoes over their doors and so on because even now people cannot get away from daft and pointless superstition and belief. It was only a little while ago that christians went out and killed women and children because they honestly believed they were witches - that these people could cast genuine magic spells. Hell, there's still cultures in the world that still believe in forms of magic - voodoo and whatnot. You could consider people now in this modern age of technology and knowledge as vastly less superstitious and prone to gullibility than those of thousands of years ago. But for crying out loud, look at them. Humans are still bloody idiots.
They escape the stupidity of one god only to fall for the next one to come along. They actually sit down and consider the beliefs of Scientology as valid, (lol), the beliefs of christians as valid, (lol), there's some that honestly believe that breaking a mirror will result in 7 years bad luck, still say "bless you" when someone sneezes even though the bubonic plague ended a long time ago. They cross their fingers thinking that's going to help somehow and pay attention to their star signs/mediums/fortune tellers/crystal balls/tarot cards etc etc and so on.
Now, you might not personally believe Harry Potter is real, but there's an insane amount of crapola that you do - for no good reason - based not upon any facts, but mere assumption, old wives tales, personal opinion.
You think the people of 2000 years ago weren't "gullible yokels"? Hell, even modern day people are.