That is correct.Once you hit it big,that memory will haunt you at least until you get back to gamble again.In terms of quitting it is much easier to really quit once you have had a really bad day in gambling and these days are like alarm bells that reminds you of something,in this case that it is worthless to continue gambling,you could have used that money in a much better way then throwing it all out in the casino.
Usually when people take a decision on these days to quit gambling they usually succeed,in here I also include myself when I hit a super huge loss one day I promised to stop and I rarely play very little money now.
If they are really willing to quit, they can do that but when they are just devastated and frustrated there's a higher chances that they will only want to stop because of that emotion they are feeling. Quitting gambling is not so easy especially if you gain some happiness and you gain some money to it, you will hardly stop playing, but if you are eager to stop you will eventually stop.