Many people do gamble casually. When I used to play Dota, there were sites that allowed you to bet your ingame items on pro league matches. It looked like some childish way to gamble, but these items could be quickly sold for fiat money on steam and some were quite valuable, so people were betting the equivalent of 10-100 every time. I'm sure that it's still popular.
I think there are still sites like those, Dota2Lounge, and recently I have searched for it and it still works. What's awesome about it is you just have to give permissions and login your Steam account. For me, it's not a childish gamble knowing that it involves money. It just seems games are just for kids but I beg to differ. It is still popular in my peers.
If you really think about it, everything in life you do is a gamble. You decide to take a vacation, there is a chance the plane could crash and you end up dying. You decide to work at a new company, maybe you will get assaulted by a coworker. Every action has a consequence which means every decision we make can be considered gambling.
I think like that sometimes, especially when an important decision was done. It has always come to my mind that other possibilities could have happened, but it's already there and you can't change anything about it. But the
important thing to do is that you won't regret anything that you have done already, because why do that decision if you don't like it or something? Unless you are left without a choice anymore, you only have that one regretting the decision, but I don't believe that. There is always a way, just like gambling, you decide to win, and hope that you do. Don't regret if you lost, because it was your choice to gamble more.