When to leave is the hardest decision a gambler is facing, for me you need to know your limitation on taking bets like if you lose 50$ then tell yourself thats enough.
Or if you won a few hundred dollars breathe and drink and tell yourself thats enough for today.
Yeah what you said is the right, We should take always a good decision when we talk about gambling, because here we talk about money and this is too risky. We should make some rules and limitation of price before start gambling, Following this rules is obligate to safe us from lossing huge amount. People are greedy include me, so we should stop ourselves using theses rules.