To be honest, I never think about if I really know how to trade or not. All I need to do is buy at a low price and sell at a high price, and I am very agree with that.
With only following the basics methods of trading, we could always make a profit in every day, but unfortunately, it's not easy as we say because it will need more learning and more experience to know the right time to buy and sell.
I suggest you do not think about that because you will be confusing to determine the truth, the best thing you can do right now is continue to trade, try to buy low and sell high, and you are good to continue.
The only key to success in trading is buying low and selling high but buying low is really a challenging task as it really takes a lot of research and knowledge before you know the perfect dip. Any new individual who would join trading can even have profits if he invest in any random coin when the coin is deep seeing the yearly graph ratio and waiting until the expected price is been reached.
This will make profits for those peoples much easier and also not much skills are required there. But a professional trader can find a dip in any coin he is interested in and will invest at a perfect price setting a stop-loss and waiting for the expected price to reach.
I definitely agree with you that is the only key to success in trading. But we know not many people who can buy low and sell high, and many of them have big greediness in trading, so they want to make a bigger profit.
In the basics of learning trading, buy low and sell high will be work in many situations but the problem, we cannot determine when the price can reach the low price and when the price can increase.
And if that is happening to us, then no other way for us to learn more about trading so at least, we can predict when the time comes.