In order to learn from past mistakes and to ensure that you consistently execute your trades based on analysis rather than intuition and emotion you need to journal your trades and regularly study your own track record. A trading journal is an invaluable tool for traders to track their progress and insure that they are truly following the trading plan. By documenting every trade, a trader also has the data necessary to evaluate if a trading strategy is the problem or whether emotional/human elements are interfering with the strategy.