Documenting your trades is the only way to improve. How can you increase your successes when you can't remember your failures?
While its not thrilling to type or write in your losses, it certainly is on your wins. The act of documenting your trades reinforces the positive and helps you learn from your mistakes. Additionally, you can develop extra trading strategies that can help your moral - while I'm all about shooting for the stars, if you've had a few previous below average months but you finally meet your goal... you can stop trading, seal in your wins for the month and pick back up the next month.
If you don't keep a journal now, start - and I am willing to bet you'll see yourself improve (even if you're already really good!)
If nothing else, you'll have a list of your trading activity to get a head start on your taxes before your 1099 comes in!