2+2=5. If you've ever read 1984, you'll realize that while there are objective facts, independent of our observations or beliefs, there are socially created facts. Socially created facts sounds oxymoronic, because it is. The point is, as your OP mentions, if a person is obstinate in their POV, they will refuse to change their mind to any new information, or at least attempt to justify the new information that contradicts their belief.
Societal norms/ideas/culture/religion are very powerful constrictions upon the human mind, yet ironically, where would we be without them?