It is subtly different, in that people are generally mis-reading pain expressions from lack of experience, but it's also in many ways a cultural bias around how pain is expressed:- "Well, we expect stiff upper lip from people, but I know if I stub my toe I yell, therefore no yelling = manageable pain." But that startled pain reaction only applies to unexpected injuries, not so much "Oh, shit, this is going to hurt," or "so this hurts, as usual".