Not really knowing the odds of the games you play. 99% of people don't really know what is going on with the different gambling games, that's why you see so many people playing slots even though they are the worst with extremely bad odds, blackjack and others are far better but still disadvantageous at the end.
Lol...I played slots games couple times in the past but to be honest I played it because I just curious about such games. As you said, 99% of people who plays it don't really know what's going on, I am maybe one of them. All I knew about the game at that time was just spin and spin. I even don't know how much the minimum bet for each spin was.
That's why they also have so many slots with so many lights and huge prizes to attract people to them. They would win money regardless of people playing slots or not but the more slots they play the faster and better for them, if everyone was playing only games like blackjack the casino would win less money.
that I collected from captcha clear per hour and also made small deposit ) .
before learning that once you lose, forget it and just move on. It can never end up well. The cruel part is when you bet that big amount, you will want to try a bigger thinking after all, you have taken the bold step already, until you see a zero account with your eyes wide opened. 
