What was the unique opportunity of that kid some streets down here that got gunned down when he was 10 years old?
What was the unique opportunity of the record amount of slaves worldwide? (by the way, did you knew the world has more "traditional" slaves now than any other time in history?)
Or... what is my unique opportunity? Being in debt? Not having a single important connection? Going to shitty university? Yes, I am intelligent, I make games, but I see lots of people with less skill than me earning millions, just because they were friends of someone somewhere or their dad was the minister of something in the government. Ultimate example: Eike Batista, that CLEARLY is incompetent, since none of the business he started on his own had profits, yet his father that was the mining minister obviously had a hand in Eike 90% accuracy in finding minerals in areas previously surveyed by the goverment during his father tenure while this information is "secret" and private companies should not know, and the government recently happily handed him billions and kicked out thousands of people from their homes so he could make his lastest failure project.
[1]and perhaps others like Zuckerberg more so than Buffet, who could probably have somewhat more slowly honed his investment skills and found patrons whilst working the sort of day job people with ordinary middle class backgrounds can easily get.
While that's somewhat true, the fact remains that almost all of the people on that list might not be there if they weren't born into at least the upper middle class. They took advantage of the privileges given to them, so it's not like they don't deserve it. But there are likely those from poverty and the lower middle class who work their ass off setting up businesses in things they have access to, mainly restaurants/stores, and only ever move into the upper middle class as hard as they try and as gifted/intelligent as they may be.