Only a mentally strong person who has control over emotions and have money management skills would be the real winner here and will become rich eventually.
To tell you honestly, those persons you are referring to in that statement are mostly not present in the gambling world.
Why? In the first place, if the goal is to be rich, why do gambling? If a person is good at money management skills, why do gambling?
In the world of gambling, there's no such thing as controlling emotions stuff at 100% since that was human nature. What we are trying to keep up with gambling is trying to be responsible all the time regardless of winning or losing. Believe me, even if a gambler does have continuous wins and is able to cash out as always, that won't lead to the path of being rich as these winners will always find a way to experience that wonderful feeling of being a winner and will continue to face the risks in gambling, in the long run, chasing that purpose.
very rare that a gambler can be a winner at the end because most will continue playing even after winnings. but for some who can have this money management skills, after winnings, they are allocating some funds to savings or business. if a gambler can do such job, he won't go totally broke. now the problem is, if he won't stop gambling, and if he will use the money that he saved for gambling again, then he will go to that route of being broke. that's the dilemma of most gamblers, they can't stop up until they are already broke.
and for those with such rich mindset, after winnings, they will set aside the funds for possible business venture and not go back to gambling. and the number of such people are few.
