Maybe money really does make you happy, at least in the moment. People are actually very visibly happy when they receive money. The larger the amount the more they exude happiness.
I suppose the truth might be closer to: money doesn’t keep you happy. Like any other material object, we tend to lose our interest once we’ve obtained what we wanted. Then there’s nurture.
Money is everything in society; we define ourselves by our incomes. We flaunt, not our money, but our status, our wealth, and we celebrate how easy it all is for us. We like to show off and money is a big deal.
The problem, in my humble opinion, is that money is so powerful to us now that the great majority of us are willing to ignore ethical considerations when sufficient amounts of money are involved. Money can make you a bad person, and maybe money isn’t brainwashing you so much as it is consuming you, incapacitating your ability to empathize with those who are transferring they money to you. You might not even think of the negative consequences at all, so you don’t feel dirty. You are just ignorant, and that’s okay as long as you are rich.