Expectations in gambling makes you think that another win is coming, this thoughts makes you use the money in worst possible ways. When you win, handle it like no other one is coming, at least for a while, Use the money well.
Have you not ever ask yourself why your neighbour gambler won $2000 some years back and no other similar wins happen?
One thing is greed and another is self control, do you know that people love to take calculated risks all because they want to hit their target but along the line they get a positive outcome and are stucked with going back to that same thing. Winning is one thing and being able to control oneself not to get addicted in pursuit of a win is something to be considered daily while gambling. When I win i do take the chances to hold on fir awhile cause most times it's what triggers you to go overboard.