I think if you want to know, there is solution: trading for one or two years and after that, see your portfolio (profits, losses, especially drawdown), you'll know if you are good trader. If not, that portfolio will tell what you lack and it'll depend on you to find way to improve yourself.I don't know exactly how much, but the most you train and trade in forex, the more knowledge you will get aside from experience, also your confidence will be grow slowly. And if we want to define how much is it then we should feel it by ourselves, but the more capital you have it means they more knowledge you should have.