I would say, do not quit trading just because you got bad results, but I would suggest learning from mistakes is very where the money is at. I agree with you that most people do not make money because they lose during that period, they do not learn from their mistakes, but that also doesn't mean that you should be making any profit.
What we need is to make sure that we deal with a lot better results, and if we can do that, then we are going to profit. What do we need to be able to learn from our mistakes? First of all, you need to study trading, as in know the technical parts and if you can do that, then you are going to earn a lot more. Plenty of people look at their mistakes and can't see, that's because they never studied.
Yeah, learning from mistakes is great, if you study and do a fine job, then you could make some money from it and wouldn't get a bad return. Plenty of people end up with great results, but that doesn't mean we are going to get bad results each time. So if you study, and learn how to trade, then even if you make a mistake, you go back, and use what you learned from what you studied, to check what went wrong.
You should be able to see the mistake, and learn from it, and do not repeat it again. Imagine making mistakes once, and never again, you will get much better. Most of course do not act as if that's an important part. We could see this being a great deal of detail, and for a lot of reasons we need to focus on how we could get a greater money. So study, learn, check mistakes, do not repeat them, profit.