Remember the first trading lesson you learned as a newbie? Did it come from a win or a loss? A loss teaches you about the reality of the market, protects you from becoming cocky, and humbles you. When you are a beginner trader, a small loss is not a terrible thing. Losses teach you proper trading risk management strategies and techniques and respect for the market and prepare you for long-term success.
Remember the first lesson you learned as a beginner trader? Did it come from a loss or a win?
Successful trading strategies are always based on the analysis of past losses, not on the analysis of past victories.
This follows from the scientific approach to knowledge of the world. A scientist can never prove his scientific hypothesis - he can only refute it. You can run 1000 experiments and all of them will confirm your hypothesis, but the new 1001st experiment will disprove it.
And the fact of the refutation of the hypothesis will give the scientist new knowledge.
Scientists always learn from their failures, not their victories. The same is true in trading.