If you think about it, Hard Work is an Illusion. No matter how much you may try, there will always be winners and losers.
Also, he would know that you're a prince because a princess just called you her brother. The writer or translator should've had him say "what brings the First Prince", which is not only a distinguishing trait that the princess didn't mention but also shows he's fairly educated of your political position-which also lends to him to being aware of your medical history. Or maybe not, but at least it would be better.
@Geohie The issue is the dialogue shows an inconsistency. Davy acts as if the guy already knew he was a prince when pushing him, because he called him Prince afterwards, when the guy is just as easily reacting to the princess calling Davy her brother.