There is a meaningful difference between trading to win and trading to not lose. The average person feels more psychological pain over a loss than they feel pleasure over a gain–particularly once they have already “booked” that gain mentally.
When we enter a trade, we expect to be paid out. Mentally, we book a potential profit. When a loss materializes, it is the unexpected event–and we respond more strongly to the unexpected than to the familiar.
What is the solution to this dilemma? The answer, surprisingly, is to book losses before they occur.
It’s human nature to not want to think about such unpleasant things as losses. But by knowing our maximum possible loss in advance and by mentally rehearsing what we’ll do on those occasions when the loss occurs, we normalize the losing process. That divests it of its emotional grip.
We can never eliminate loss from life or trading; nor can we repeal the basic uncertainties of markets. What we *can* do is develop an edge in the marketplace and, over the course of many trades, let that edge accumulate in our favor.
Source: http://traderfeed.blogspot.com/2006/09/trading-to-win-vs-trading-to-not-lose.html