Well, a gambler needs to be educated and willing to learn these realities, if he or she wants to become a responsible gamblers.
What I have experienced that most of the gamblers lack in discipline and they are motivated by their emotions and gut feelings that they are in gambling not only to make money but rather they will change their fortune by gambling.
It's really sad to see that gamblers are not really willing to learn from thier mistakes and even big losses will not set them off. Too much expectations will never lead to success in gambling.
As what I can see from most gamblers they tend to chase their losses as what the OP has stated, coz they think that they can recover them by the next turn but in reality it's not that simple coz there are so many factors involved when you are gambling. I also agree with what you were trying to convey that too much expectation leads to disappointment, in all honesty those who expect too much specially in gamblinf ends up the most irritated, and I am speaking through experience as what I did observed from my neighbors who are already seasoned gamblers. I have even witnessed someone from my area who lost $500,000 in just a week of playing a game, and I didn't understand how such a person can handle such loss or is he still okay with it, it's just so unreasonable for me, if I were to be asked.