I think Snow meant it figuratively but it is the classic nature vs nurture debate.
Two twin boys, from the same mother and father, sepearated at birth.
David remains with his parents whilst James is given to a king.
David lives on a farm which is struggling to survive and learns the value of hard work.
James lives in a castle which was probably doing reasonably well at the time, had servants and what he wants he gets.
David likely learnt the value of other people, the benefits of working together, the different skills people possess, more hands make less work, etc.
James likely learnt that people are expendable. There is always someone else willing to do what another person won’t, people are only valued by their usefulness, etc. George described Jack as another “dalliance” for James, so long as she was offering what James wanted she was useful but when she needed James to help her, he discarded her. (Makes you wonder what sort of life Abigail would’ve had if she’d had to marry the real prince James).
All magic comes with a price!
Keeper of Felix