I don't know; I think people in general are just not great at this. Successful people tend to underrate luck and overrate the brilliance of their own decisions, but the rest of us are prone to either reversing that and blaming everyone but ourselves, or being so determined to take accountability (or just depressed) that we become overly self-critical, or simply not understanding why things happened the way they did and reaching for any explanation that resolves the chaos into something narratively satisfying.

If there's a single unifying fault to the unsuccessful people I know (for any definition of unsuccesful, including my own failures) is that they're precisely bad at working out why they failed - if they even think to ask the question. The successful people are generally much clearer that it was studying hard or networking or natural talent that contributed to their success. The latter group may have people who don't realise luck played a part, but they massively increased their chances of good luck by the aforementioned behaviours.

Yep, many successful people greatly underappreciate the effect of simple dumb luck in their lives. And often they just make up complex reasoning chains, even wholly believing them, that more of it was in their control/talent, etc.

Nonetheless, there are many successful people I would gladly listen to for advice, though they are often successful in a different meaning than what venture capitalists would use (e.g. parents with great kids, managing to keep a healthy work-life balance, happiness, and maybe even having time to spend on some cool hobby project -- you are heros!)

Intuitively, that'd make sense if that unsuccessful person eventually found success, otherwise who knows if they actually picked up what made them unsuccessful in the first place?

Luck is a huge factor in success, so that logic leads nowhere. If one of the quacks selling how-to-succeed recipes had got it right, everyone would do it by now.