Gambling is for fun and enjoyment and those who enjoy this way would not worry much even if they lose the money. But for those who want to just make money out of it would have difficult time as they would want to keep wining every time.
Mostly people start it with good intentions like you have got. For fun and enjoyment but very soon they got the inner view of game, the addiction to money. They bind themselves with gambling slowly. Very soon, greed for money attack them and they are victimized. This make their start with gambling, the harmful. Now, they really dont care about fun or enjoyment or any such thing related to it.