What is trading discipline?

It is the art of continuing to execute the plan regardless of profit or loss.

The major taboo in trading psychology

is being influenced by jealousy, fear, desire, lack of confidence, and so on.

Traders are prisoners of their own thoughts; you must be confident, you must be confident, you must be confident. A loss does not mean you were wrong; even if the market signals perfectly align 100%, you cannot control which trades will win and which will lose.

Respecting the market means not only respecting the trends but also respecting the fact that a correct trade can still result in a loss.