I think no matter how good you are as a trader, you will not always get every trade right and you will face a trading loss every so often. In my opinion that is perfectly normal and part of trading and risk management prevents that loss from having a big impact on your overall portfolio.
No trader likes to record a loss, at least I never met a happy loser. I did come across an article on the Paxforex blog which made me think about it (Losses As Inevitable Part of Forex Trading). I guess everyone has a different measure for success and failure, so I was wondering what you classify as a good strategy for yourself? Do you look at how much money you generate, the percentage of your trades you got right, etc.?
I ultimately measure it by how much money I have earned and if the returns are consistent.