youre absolutely right my friend, money management is the key to this whole thing.
you place a trade and if its going your way, great if it isnt then money management gets you out.
the purest way of trading in my humble opinion is a simple entry and exit rule with a stop loss that has already been accepted as a loss in the traders mind.
discipline to follow your given signals is paramount - 2 losses and the untrained mind says that 'next time, ill wait' - thats the one that would have made the profit - guaranteed!
havent read the book you state, but i have read one called 'the way to trade' - thatis a relly good book which covers more than anything the psychology of trading and learned me more in a reading session than most so called 'courses' ever did.