For.

Reason 1: Some people feels unhappy and empty even after having too much money that they don't even need.
Reason 2: Happiness is not a form of money, it's a form of a thinking; if you can think that you can be happy without money then that's happiness.
Reason 3: Happiness is not a thing that you can buy with money so one can't be un-happy without lots of money.

That's all from me now.