You're right. When someone decides to gamble, he must be ready to lose money. There is no way to avoid losing money in gambling, each gambler must experience losses. That's why we shouldn't use a big amount of money in gambling, it is because the money will tent to lose. Even if you can win sometimes, there should be some losses as well. Well, gambling is surely just for fun. Or for trying your luck only. We must always remember that we don't expect too much to gain money in gambling!!
Absolutely, gambling, in my opinion, is a losing game. When it comes to gambling, the only certain outcome is lose. You must lose, but winning is not guaranteed. As you mentioned, a gambler who understands that winning is not guaranteed will gamble with caution because any money used for gambling has already been lost, so he will naturally be cautious with his stake and will mostly gamble with money he can afford to lose.
Without a doubt, there are gamblers who understand the risky nature of gambling, but desperation and hope drive them to gamble recklessly in order to increase their chances of winning, believing that the more you bet, the closer you get to winning.