In the human society, there is nothing that could be produced by a single person, nor by an isolated group. Everybody depends on everybody, though these dependences are often very indirect. Nobody can claim to produce a slightest thing without any assistance at all. The very fact of one's existence is already mediated by billions of other people. In our everyday life we use numerous commodities; we need food and clothes, shelter and protection, learning and education, instruments and tools. Our free time and our privacy cannot come but from the society. Our thoughts and feelings are culturally determined, and our ides reflect social needs.
That is, whatever one does, one is never alone, and whatever one makes is made by the society as a whole. The formation of a conscious individual assumes the millennia of common experience. One's personality is nothing but a collective effect, the crest of the wave.
There are no "self-made" people; we are all made by the culture we happen to live in. All we can achieve is determined by the specific economic and social conditions, and every our act is mediated by the history and the present of the humanity.
That is why the idea of property is logically fallacious. There is no reasonable ground for anything to belong to a single person. Every single thing is produced by the whole society, to satisfy social needs. One contribution is no better that another. The concentration of wealth and power in the hands of a limited group of people cannot hence be anything but usurpation, which becomes possible due to a wrong social and economic order.
However, the absolute sociality does not mean absolute identity. On the contrary, universal social support results in truly unique personalities, and lack of individuality means lack of sociality, lack of reason. Conscious activity implies infinity of possibilities, and each of them is implemented in a single person, whose unique formation is indispensable for the reproduction of the totality of the world.