Naivety

Naivety is a fairly common mental trait among species as has been noted by many notable researchers.

Naivety itself is not where a specie lacks knowledge in a certain area but rather, where they lack understanding in a certain area of knowledge with some species such as humans making assumptions about the nature of the universe despite having an incomplete set of data on it.

Not only that but, due to their flawed understanding, they have passed on false information onto their main populations which has masqueraded the truth from them and thus, creating a problematic situation when an alien tries to educate them on the truth as they simply don't accept it.