Commander in Pips: Because logs of software statements have insufficient information. All that you can see is lot size, entry price and exit price. But you do not see how you have entered and why you have exited. For instance, suppose you have analyzed the EUR/USD market for an hour just before today’s trading session and developed an excellent context to enter long, although your gut tells you that something is wrong with current price action, something that you don’t like in the picture. Still, you are following your trading plan. Suddenly, the market accelerates against you - closer and closer to your stop. By your negative emotions you step out from your trading plan and close the position with loss. But right after that some important data (say NFP) is released and the market explodes right to your former profit target. You understand that this falling was just position closes before release. This is very common situation for traders. The question is – will you remember the reasons for entering and exiting of this trade after two weeks or a month without fixing it in your journal? Will you be able to catch the bad habit of stepping out from trading plan or good habit of following it? Will you remember the context for this trade? The answer is no. If after some time you will not understand what you have done and why you have done it – your trades are in a bad way, it’s a wash-out. The major conclusion that we can make is that keeping your trading journal is a discipline issue, and disciplined trader stands closer to being a profitable trader. If you do not want to be an enemy to yourself – it’s better to keep a journal. All profitable traders keep a journal and review it. Yes, this is not bad idea to pass through your journal during weekend. When it will become too extended then at least through some recent trades.