yes this is the main reason according to me why ppl loose their money, they have large and senceless expectation's from forex, ppl nortmally start from small lot sizes but with a gain of little money too they become over confident and in those thoughts of greed and luck they go for big trades and then loose, some losses are also coz ppl are unable to understand the trend ( predict ) and so they loss, some ppl also do noty use parameters and depend on themselves for everything so again they loss and the main reason is not using sl which can be a life saver.