The youngest sibling is destined for greatness always. Bad news for me as I'm the eldest.
Those who are humble tend to be helped on their way by a fairy godmother they hadn't known they'd had. In fairness I think it safe to say there is no world anywhere, fictional or otherwise, that likes the arrogant. They definitely won't do well in any magical kingdom and may well find themselves getting the wrong side of it (always a bad move that, you just know it can't end well).
Never despise those who work in a kitchen or do any other kind of menial, manual job. They are the ones who if there is magic in the air will benefit from it. Never ever forget where you came from and always be grateful for what you have.