Of course, when we only use the amount of money that we can afford to lose to gamble and accept the outcome of the result will help one gamble responsible. This boils down to having self control whenever you are gambling. A lot of gamblers finds it difficult not to think of making profits when they are placing a bet and this can trigger them in using more than the amount of money that they can afford to lose to bet. When they lose their bet, they wouldn't want to let go of their losses.
I also believe that greed is the main reason for major losses in gambling. The unwillingness to let go of something you’ve already imagined as yours leads to reckless actions and risks you're not prepared for. And by the time clarity comes it’s often too late. That’s why it’s important to have something or someone who can stop you in time, remind you of your limits, and bring you back to reality before the thrill of gambling completely clouds your judgment.
The emotional struggle of reminding yourself about the limit you can easily carry without being frustrated at the end continues until you are no more gambling, gambling is emotional where sometimes we only realize we have gone beyond limit when it is already too late just as you said, it is should be a personal thing to control this emotion without waiting for anything or anyone to stop us, we don't have to wait till it gets bad too before realizing, the discussion over here is encouraging only if we allow it play an important role in our individual references, so we don't talk one thing and do another.