To be honest, I have never had a big win as a gambler but many times I have made some good bets that allowed me to earn some revenue. I would say that someone's latest big win as a gambler should be to have control over his/her emotions during gambling.

It's somewhat philosophical but it's true because if someone can't control his/her win related emotions during gambling then that person is much likely to get addicted to gambling for chasing big wins, and that is not going to be good at all.