There are times my hopes are high to get a win irrespective of my taking the earning aide of it as secondary (not compulsory) on the grounds that my resolve is that am gambling for the fun and entertainment that is embedded in the activity but as humans been involved in an activity that money is involved that by chance/luck you can win an amount that can change your life, that inclination to earn from it will randomly offset at some point but it's left for the gambler who have accepted it to be a funfair activity to regularly remind himself that gambling isn't a source of making money so not to get addicted at it.
It's normal for we humans to hardly just make fun out of what has so much involvement with money, there will always be that tendencies of wanting to definitely do some More or get more out of it but then when this urge get so much greed creeps in and the later part of it grows into addiction so we should learn to control ourselves enough to get the fun and entertainment out of it.
Understanding that gambling isn't a source of money as you rightly stated is really important because knowing this will definitely bring to your consciousness that you should just have fun and focus less on making money from gambling els you may never get to have the fun that comes with gambling