I believe @OP is trying to give advice about what to do when one has won an amount while playing in a casino, this is also the reason why there is an additional text of strategies for protecting one bankroll and if you look at the content of the post, you can see methods on how to manage the bankroll.
I know it's not easy to know the right time to quit for the day but once you start feeling unsure of your prediction on a regular, it should send a strong signal that it's time to quit.
If we know our limits and the extent to how we should go when gambling, then we will be able to do the right thing as long as we are not being emotional about our actions as well, it's not a must that we must get all our bankroll exhausted during a one time bet in a day, when we see that luck is not coming, it's a wise decision to quit for another day to come and continue gambling when all things are well set.
I highly agree, that moderation is one of the huge factors in responsible gambling. controlling oneself from the urge to gamble and being able to stop when in green can be said and considered to be as an action to winning wisely.