Honestly, this is the first time I have heard the word "serendipity" and its meaning. I can say that I have experienced such luck more than twice, and one of them was in a physical casino. It happens like the example that your AI described. I didn't go to the casino for gambling, it was for a company "celebration" in one of the conference rooms that some of the physical casinos have. After it ends, a colleague asks me if I want to join him in the gambling area. I said yes, but not for gambling, just for a drink and company. My friend sat at a blackjack table, and after some time, I got bored, so I decided to sit at a slot machine near his blackjack table. So I put in $20, and I ended up winning $550 in less than 20 minutes. Pure luck without any motivation just to "kill" my boredom.