This is something that not only happens with gambling but it is very common at other activities, an example of this are video games, in which a person may want to play for some more minutes, minutes which then morph into hours.
Then it is important that people set themselves a time limit when they gamble, something which is trivial these days as even the most outdated smartphone out there should have an alarm and allow us to not gamble for a longer time period than what we intended.
I think we've all experienced it, whether in video games or gambling. And indeed, it can change everything because by continuing to play whatever it is, we can forget what we want to do. And if it's in gambling, we can experience defeat after defeat and if that happens, we can only regret it and lament why we didn't decide to stop and leave the casino.
Using an alarm to warn us can be a solution to stop immediately but we must really be able to follow those limits. Many people have limits on gambling but fail to follow them because the temptation to gamble is too hard to resist.
Like you said, even with an alarm to warn us about the exceeded time in that activity, it is very hard to stop it especially when we are currently experiencing lost that is if it is gambling but for other activities like video games an alarm could give just the right amount of awareness to stop it and attend to activities that are of more vital needs.
I think for the gambling aspect it is more difficult to stop it even if you are being alarmed about it because its hard to accept defeat and try later and only with a determined mine can you stop it and if you are a man of great principles.