If you have been gambling for long, I mean for a veteran gambler no amount of winning streaks could get into his head because he has seen and had many experiences with the act. He just accepts the winning streaks as they come in, knowing well that after a win comes some losses too. Gamblers that are mostly carried away are the newbie gamblers who haven't undergone through some of these experiences, as a result they get easily carried away.
I got your point, you are saying the truth, there's no way winning from gambling will get into an OG in the system but we should also get it straight that it will also depend on the amount the old gambler won, as an old gambler let's say you have been winning big, May the amount you have been winning is small and you eventually win something very big, the excitement might be much but wouldn't get to the level when newbie gets such winning, I think I miss out something, some old folks in gambling still react as newcomers, there action will even get wondering if they are actaully what you think they are, so it seems this is an individual differences not actually all old gamblers can withand such to pipe low.
Let me not doubt you are trying to say as you did made some valid arguments here if we are to consider the very different nature of every man. Humans naturally are unpredictable in what their reactions can be from an event. But I just know that very many out of a total number of old time gamblers wouldn't be so overexcited that they get carried away to think it will always be that way.