Have you ever blown an account? I've never met a trader that hasn't. The scenario usually plays out like this. You have a few profitable trades under your belt and you get a bit of confidence, and you see what you believe is another good trade, but it begins to go against you. No problem, "It will come back", you say to yourself.
It doesn't come back.
But then you think, "This is just a better price", so you put more on the trade as it continues to lose you more and more money. The larger trade just accelerates your losses until it hits you, the dreaded margin call. Your account is all but gone, all of your hard work and profits negated by a handful of trades. So what happened?
The key to surviving in the Forex market is minimizing your losses. The only way that you can really do this is by using stop losses. They allow you to manage your risk, without a stop loss your losses are essentially capped at whatever money is in your account. If you use a stop loss then your maximum losses are under your control. Small losses are easily recovered; large ones destroy your account.
Remember that it takes a 100% win to recover from a 50% loss, but a 1% loss is returned with a 1.01% win. One of the most common responses trades give to this statistic is "minimizing my risk minimizes my reward", and my response it that you can't make any money when your account is wiped out in a handful of trades.
Keep your losses small by using a stop loss, because the longer you can stay in the market the more chances you have to make money.