For my cohort, it was luck, ability to relocate/travel and the gift of the gab.
I know people who have achieved phenomenal success. Interestingly, they were the people who you would least have expected. They didn't try hard, they didn't work, and they dossed about for most of their teens and twenties.
But they were good at blagging, and picked up "jobs" in various European countries (largely because they couldn't get any work in the UK). Twenty years later, they are now Senior Heads of Department at some global powermakers.
No-one else I know from my cohort, no matter whether they went to Oxbridge or into a trade, whether they took risks or not, whether they started a business or not has particularly got anywhere. And there were people who should have seen successes. So many people I know took risks, jumped out into the unknown, worked hard /smart and they ended up nowhere.
It's a bit of an interest of mine, this subject, and over the years I ask people I meet who've achieved extraordinary success how they did it. As a rule, they tend to be in their 60s and 70s now, and they all say the same thing: it was luck. Right place, right time.