If my father left a well-insulated house with a fireplace to my siblings and myself, I would be incredibly selfish to say that my siblings would have to sleep outside in the snow because I cut the firewood all by myself. This has implications for the human family.
Your situation depends on a long chain of discoveries and improvements made by people now dead, gone, and forgotten. Are you warm in the cold weather, then you depend on people who invented the furnace, the chimney (Medieval Europe), back to fire -- which was domesticated hundreds of thousands of years ago.
Did you eat? Then not only was your food grown by others, but those others depend on others long ago. The crops were recently modified, but cereal crops were originally bred by people lost in the mists of prehistory. For that matter, the discovery of agriculture -- that when you put seeds in the ground they produce new plants -- was a great improvement in human life, and it was a specific discovery. It was so far from obvious that it went unnoticed for more than half of the time that humans have existed on this planet. And milling grain into flour was another invention.
That you have not perished from cholera, or a dozen other plagues is probably due to public sanitation, which is a fairly modern invention. The vaccinations which conquered first smallpox and then a dozen other diseases can be traced to historical persons -- Jenner, Salk . . . . Even the unvaccinated benefit from those vaccines, because they decrease your chances of being infected. (Most of us today haven't been inoculated against smallpox. The previous generations of inoculees eradicated it, and you are protected against rabies by your dog being vaccinated.)
So our life is eased, even preserved, by conditions which our society has inherited from previous generations. Once you see that, you have to ask what share of that social inheritance does each person receive.
The other issue is that the people who are successful now are successful partly because they have lived in the particular environment our society is. Does some rock star sell millions of dollars worth of records? He would not be one tenth that rich if nobody had invented the recording media. (And those would not have been invented had not other inventions and discoveries preceded them.)
Strangely enough, it seems that the people who are most aware of this are the people who are closest to being independently creative. Steven King wrote his works by himself, without collaborators. Sure, he made his fortune because of the modern publishing economy, but he is more nearly independent than most others with a high income. King, however, is an advocate for higher taxes on himself and those with similar income. Then, too, Obama gets more of his income from his independent writing than from his presidential salary.
Mitt Romney, on the other hand, made his fortune bringing other people's money to finance other people's companies. The people whose money he managed were, for the most part, satisfied with how he managed it. Nobody with any understanding of modern business, however, will argue that no money would have been available to those businesses without a private-equity firm.