Aristotle argues that Happiness (eudaimonia) is not a state (such as a pleasurable feeling). Rather, it is an activity (Nicomachean Ethics, 1098a16). Pleasure often accompanies activity but it isn’t itself happiness.
As is clear from Aristotle’s list of happy-making activities, many require the possession of property. One can only be generous if one has the power to dispose of one’s property by giving it away. One can only purchase something for a lofty goal if one owns the wealth to spend. Hence, one cannot be happy if one owns nothing.
Even the poorest of people can be generous with what they have. What often surprises wealthy travelers is how poorer people can be happy in giving what they have away. It shouldn’t be a surprise if Aristotle is right.
According to Aristotle, happiness is only possible with the use of our powers. Actualizing some of those powers requires that we own objects. Hence, happiness entails ownership of property.
It follows that political organization should be aimed at allowing individuals to maximize those powers and to use them freely to their own ends. It shouldn’t be aimed at removing or strictly restricting those powers.
It follows that you will be happy and you will own nothing is false.