Yup, because if you know the limit of your gambling capacity and you don't give in to your emotions, then there is a greater possibility that you will be more successful in your gambling. I mean you are more likely to win some people control their emotions in order not to be greedy and avoid chasing losses.
I agree that It is also important that you have more experience in gambling and know some skills, but if you don't have any ability to know this field then it is better to try first and test if gambling is really for you. Some people are only influenced by their friends or colleagues and there are also other people who are just imitating other gamblers knowing that they don't have much experience and in the end, they will be sad because they lose more than winning.
That's why as a concerned citizen, who knows the status of their lifestyle is also unhappy to think that the money that should be spent on their daily life is just lost through irresponsible gambling.
Giving into emotions can be dangerous, but successful is very subjective term. I would take it as being successful when we don't lose everything by playing everything we got, or even more then we budgeted. That's a win in my book. I don't necessary wait for huge profits in order to be successful. Just minimized losses. As long i am losing what i am affording to lose, i consider myself a successful gambler. That might be a low bar for someone but it keeps me straight and far from the trouble and deep end. And i consider myself greedy, not so desperately greedy i would play with a loan or anything like that. But i gamble with winnings sometimes, maybe with too greedy attitude, but that what gives me big wins sometimes. But only sometimes.