Not to much compared to you, maybe around $100.
In my case it's not an one session, but it's one bet because I want to try "go big or go home", unfortunately the result is go home and I feel so bad at that time. I think each gambler had suffer a big lose at least once time in his whole life.
This is something that it has happened to almost every gambler out there, since it is very easy to lose control of yourself during a few moments and then make a big bet that you later regret, however for the majority of those gamblers those are isolated incidents, as they realize the mistake they made and they regret their actions, so the next time they are in a similar situation they will remember what they felt after losing so much money and avoid gambling under those conditions.
I agree with you that if a person feels remorse knowing that gambling is high risk he can easily avoid gambling. All gamblers have faced this situation at least once when it comes to betting some gamblers do not have a problem at the moment but are likely to develop an addiction in the future. They can take steps to control themselves. Many people who started gambling just for fun have become addicted to it. This addiction pushes them towards various vices they start doing bad things to earn gambling money. Gamblers lose control when they repeatedly gamble to win back money lost in gambling.