I think being concious of the fact that in trading, there is what we call loss and gain, that will help you to know that trading is a 50 50 game. It's either you win or you lose, but what happens to your mind when you lose, because I know when you win, you definitely have excitement in your hearts which helps releave tension, but losing is something that messes with your mind, messes with your efforts and make you feel like to quit.
Another question that should come to an Inividual mind is that, is it good to quit after having a heavy loss? or it is good to look at the future ahead and try to look at the bright side of trading, gannering knowledge and experience from your past mistakes to make the present trade winnable.