My worst mistake in gambling is the usual losing all the winnings.
Since I get the winnings, I feel lucky without realizing that is the start of temptation. In the end, I ended up losing all my winnings plus my capital. Regret is part of gambling life.
That's why we should stop if we win. Gambling is a risky game, risky to lose our money. Winning from gambling is a fortune, and luck rarely comes. So do not force your luck, remember when to gamble and when to stop.