Before such an opportunity is very difficult to resist and many are hoping with each game to win a very large sum.
I assume that those people who wants to have fun in gambling with their friends are rich people, because there is no person who lives a normal life that would happily go to gambling everyday just to have some fun even though he knows himself that playing gambling could result on losing money in exchange for entertainment. But the point here is "We are losing money" and money is important, just like what he said it is not easy to be earn so we have to value it more.
Sometimes knowing your limitation is not enough to avoid losing money in gambling, because sometimes you go beyond your limitations just to satisfied yourself.
When the person is saying that he/she is just playing for fun but gambles every single day regularly, I think he is not playing for fun anymore and is just addicted already to gambling and chasing previous loses.