Some of the games that they may think are good and seem to have tantalizing odds are in fact nothing more than odds, all games have odds and that means all games have no certainty except when you are lucky. Quite reasonable, I agree that if you want to win then you must be prepared to sacrifice your money in a few or dozens of attempts, so that means if you want it means you must also be prepared to lose, don't be egoistic because this is a game about luck that never escapes defeat, so you must first understand the real concept.
Building a successful career in gambling sounds too vague. What does it mean to get one big win that will bring a big jackpot, or to win a certain amount every month or week? It seems to me that this is only possible for a few players, everyone else will lose more than they win, this is what the entire gambling industry is based on. If you think differently and believe that someday you will start winning, then this is unlikely to happen by itself.