It's gambling, not trading or investing, so your confidence means nothing in gambling.
It's game of probability and luckiness, and whether you are very confident, it does not increase your probability to win with your bets.
With gambling, confidence is not important, the important factor is gambling responsibility. You must afford to lose your gambling capital, but even so you must gamble very responsibly to minimize your potential loss.
These are the real golden words that should be in the first place for everyone who plays in a casino. You can't be sure of anything when it comes to gambling. You should immediately get rid of all these fictitious stereotypes. You need to look realistically at all the circumstances, and not succumb to the illusion and the atmosphere that is created around the casino.
I understand that sometimes there is a huge desire to immerse yourself in this world of games in order to somehow distract yourself from the real world, but this is dangerous.