In domains dominated by uncertainty like poker or trading, a "good outcome" does not necessarily mean a "good decision." This is known as the trap of "Resulting" (outcome bias).
The 4 Quadrants of Trading
1) Good Process + Good Outcome = Good Trade (Expected)
2) Good Process + Bad Outcome = Good Trade (An unavoidable probabilistic cost)
3) Bad Process + Good Outcome = Bad Trade (Just luck; leads to long-term ruin)
4) Bad Process + Bad Outcome = Bad Trade (Expected)
Practical Approach
During weekend reviews, grade yourself with a pass/fail on "Did I follow my rules?" rather than looking at the P&L. A loss taken while following rules is a "good trade." A profit gained by breaking rules is a "bad trade" and a seed for future catastrophic losses.