It is fine to be greedy as a beginner in gambling, you probably don't have any idea about gambling and you think it's going to be easy.
It's stupidity when you have lost a lot of money and you learnt nothing from that only to end up hoping that one day you will win big money, even when you end up getting lucky your losses might still be more than what you just won.
That's a common expectation in my country. I get to see that a lot and I believe it's because those who gamble and win don't keep their mouths shut.
Some gamblers are not actually the ones that advertise themselves and their winnings to other gamblers. If you are the type who plays bets in betting shops, which are popular around our country, you will notice that when a player wins a bet in that place, irrespective of how crowded the place might be, those cashiers and attendees will somehow talk about the winnings, which others who are there will get the update on, and from there, they will task the player who just won the bet. Sometimes these people do this just to let players know that people still win here.
The question is why do people still gamble in a betting store nearest to their homes or working place? Or there is some kind of luck and benefits in winning and catching the attention of others because of your win because it's certain they will come for you to ask for a share.
It's also not even safe, because if that amount won is very big people will mark your face, they will probably monitor your movement till they come for you.