Common misconception. Europeans have never “hid” how they gained information. It’s ironic some people believe this because the only reason the accomplishments of other civilizations are even well known around the world today is because Europeans made the effort to preserve and promote those accomplishments.
For example, Ancient Egypt would not be as well remembered today if it weren’t for British archaeologists. The modern Egyptians don’t care about which Pharoah tried to understand meteor showers or whatever. Nobody has been a bigger cheerleader for the world’s forgotten artifacts than Europeans. Especially Northern Europeans. It is probably a WEIRD trait.
Funny enough, Europeans are the only people who do this.