I often mix them up and end up losing. I consider myself a very smart trader (ok, ok, above average atleast ?) but the problem is the lack of discipline to do the SELL and end up losing. In one of the world's famous traders words….

Your discipline should be to never let a winner turn into a loser, and never let a Trade become an Investment. You can always repurchase something back if it starts behaving better later.

For now, if you took something in for a quickie, and it ain't working out, you should be thinking in terms of capital preservation, not the next turnaround or bounce.