Based on what I have witnessed in some compulsive gamblers, they usually see some of all these signs when they are gambling but they ignore it and don't bother to make a correction, they keep ignoring it until they can no longer control it because it has become a habit. At least if a gambler begins to notice all this symptoms, they should either take a brake from gambling for some time or seek a advice from someone that can help them.
They're aware of the signs of gambling addiction, but still lack self control. A responsible gambler with a plan would recognize when they are losing too much and take steps to prevent addiction, without needing from others. As the saying goes, A good person advises themselves after all self reflection and introspection can be more valuable than advise from others.
You nailed it, no matter how careless anyone is, they should know they are addicted over time, but the issue is that they can't just stop, they lack that willpower and it's a problem. It may not be as aggravated as that if they understood the benefits and the true power of introspection before they continue gambling. This would have helped them to adequately being cautious and regularly evaluate their financial and mental statuses in relation to gambling. This is what some people even with weak minds have that keeps them preserved in gambling till today and the insensitive ones always perish in their carelessness.