a little confused, what skill do you mean for gambling?
for me playing gambling to test my luck there is no skill needed, unless you like playing predictions, it depends on your hobby, as far as I play gambling I don't have any skills because it's just buying luck by trying bets
As for me I think that it is not necessary to have any knowlage at all to play casino games. You mast have any game feelings or luck just to choose your lucky game, but it is not knowledge. In Forex you must know and understand the market and it is different thing.