"You'll learn more from your losers than your winners will ever provide."
Now I believe in studying success and I also think you can learn a lot from your best trades and life decisions. In fact, I sometimes think that people put too much emphasis on the value of learning from one's mistakes instead of studying what went right (and the reasons why).
Having said that, I'm a big believer in journaling your trades and taking the time to honestly examine your results. That includes our missteps, the less than optimal trades, and those flat out wrong or near-disastrous moves that take big chunks of money out of our accounts.
So if you've hit a rough patch in your trading or your investing returns aren't all they could be, maybe it's time to take a good, hard look at your records and figure out what you can learn from your losing trades. You may just improve your long-term results.