You can by beer to have fun and not seeing it as a waste of money. You can give a friend little amount of money in a way he may want to give you back but you will not collect it as you see it as small amount, telling him it is a small amount of money. Only such money like that, that are small in amount set aside should only be used for gambling. That is the meaning. The fun you see there does not necessary mean fun. Just like an ideom.
Well, the idea of gambling should be that way how you describe gambling is. However, as people learned that gambling may give you a little more of a reward for the money you spent with gambling, and so people starts to go beyond on what's supposed to be budgeted for gambling for "fun".
Now, this is where the fun will get replaced as second to making money and this is where addiction begins as well if one is not being careful on how we deal with our gambling urges and needs.
We can't deny that most of us is either gamble to have fun and make money or make money as first priority while having fun.