an English question

i think in this sense they mean a prodigy,or a kid that learns fast on it's own. a wild card in playing card games is a card that can stand for a lot of different things.it's kind of unexpected to come up while playing,but always welcome.

It means that some children will do their own thing, disregarding the traditions or values of the rest of the family. Children usually pick up our their parents behaviors and values from watching what they do and listening to what they say, but some kids don't fit into that mold and choose a different path.