Prediction can sometimes favor you or fail you, because trading is also a game of luck and there's no one person that is perfect in prediction, just that when you are favored, it looks like you're the champion but I tell you that no champions forever.
Even those who are professionals and have been trading for years, with the profits earned, cannot avoid losses. But what differentiates them is that those who are more experienced can minimize the risks of the losses they experience.
Losses can happen to anyone. Even though we have made profits in several trades consecutively, we must still be careful and prepare for the next trade as best as we can. Sometimes we take something for granted when we have started getting used to doing it.
Exactly you are right, Anything that can not be unpredictable sometimes will always make people failed. Trading is risk and we need to know that trading is 50/50 we lose or we gains, we don't have guarantee of wining in it because is always unpredictable and we can lose anytime the market is bad. Anyone is losing in trading even you are the professional you most lose no matter want, so anyone that says he win always without even loses some times, i think he just deceiving you and trying to bring you into the trading system. We can't call trading a game because is different from gambling but some think they are same.
Anything that we call game is usually a lucky thing and have is own risk management. But trading is hugh different and higher risk, without getting full knowledge and experience about it he can make you lose alot of money in a minute, before trading can be lucky to you definitely you have understood it very well and have more experience. If you don't understand trading he can never be lucky to you. But gambling even you don't understand many things on it you can predict and later you can probably win without stress, but trading you need to focus very well and understand the market very well and know with types of strategies you will used and probably profitable when the market is in your favour at that moment.