That's the nature of gambling and of people enjoying this activity

In more mundane terms, the gambling folk in general are predisposed for and susceptible to losses as well as losing all in the end for two major reasons. First, they are not rational. Well, they can be quite rational people outside gambling but as far as gambling is concerned, they become irrational beyond what you would expect of those engaged in this activity. In other words, you wouldn't really expect a frugal and judicious person to gamble in the first place

Then, let's multiply that by the effect a win big produces, which seems to be the case you write about. When you win big time hitting what is known as lucky streak, you easily get carried away losing whatever self-control and discipline you might have (which you typically don't). As I said elsewhere, it is not losses as such that make you cry, but big wins which you fail to grab and run away with in time without looking back, ever (I've been there)