Those who have regrets are those who risked a lot of money on gambling and they haven't make a lot to recover all they have spent, now they are all in regrets, you see, that's gambling for you and that's why it's not worth risking a lot of your money on.
I mostly take my time off gambling at times because of risk funds aren't available, my mind isn't always about what I will win you know, I only take risks on gambling when I can afford it, this way I already accept the possibility of losing the money.
If you can't afford to lose your money, you can either quit or lower the amount
Whenever a person does something they didn't plan on doing, they'll regret it, if the action doesn't have a positive impact. Gamblers who out of loneliness or boredom spend money in gambling will have regret or remorse. Especially when other neglected financial responsibilities begin to pop out of his mind. The blame goes to gambling, for taking all the money meant for other utilities. Hence, gamblers must have a rethink before gambling. Maybe, have other events to distract the mind from going to gamble. When in that condition, boredom, hanging out with friends are also an anti-dote for compulsive gambling, which may lead to problem gambling. Because, if they try to reduce the amount of gambling, the player still has control over the money, he can still increase it, till all his budgets get swept away. Even, during shopping, we do have a budget, but most of the time, it changes when we find ourselves in the mall. The same is true with gambling, discipline, and self-control matters. Those who lose control can windup the initial plan of spending a specific amount in gambling. There, the regrets begin to erupt.
Many criterion contributes to regrets in every gambler's experience. But, we all are expected to accept the responsibility of wagering money in gambling. The decision is ours and not of the casino. Blaming the casino or gambling for our mistake isn't helpful to the gambler. If a gambler blames himself, it'll help him avoid gambling much money next time. But, because they don't acknowledge their mistakes, the urge to repeat the same mistake can't be stopped or controlled. At least stopping when the initial funds, set aside for gambling, have been exhausted is a reasonable idea, in battling addiction. As you said, any gambler that's self-conscious of his gambling self-concept will not regret gambling, for any reason whatsoever. Some gamblers even when they can't afford to play, try as much as possible to do anything within their jurisdiction, including borrowing, to gamble. And if a gambler stops to regret his bad habit, I think he's already on his way to addiction.