Many accomplishments are mostly luck? Japan Rugby beat South Africa in a 7s match a while ago. Are the players now entitled to call themselves better than those on the South African team? I mean, sure they could, but it would be obviously false, and nothing of value is gained. This reduces all the way down to “accomplishing” choosing lottery numbers.
This got me wondering how we might prove which accomplishments are luck vs skill.
Michael Mauboussin's 2012 book dives pretty far into separating luck from skill, worth checking out, or at least the more interesting online reviews / interviews. It covers sports, investing, etc.
You can control the random seed in some games (duplicate bridge), but more often, you just want an enormous number of samples.
Even with large sample sizes there are still debates (poker [2, 3], investing [4, 5]).
So if we come back and want to assess one individual life? No idea how confidently we can sort out how much was luck and how much was skill for anyone at n = 1.
It's like watching one poker hand. We can point to the cards. We can point out that they didn't make incredibly rookie mistakes. Beyond that? Who knows.
But then... I guess you could say... The guy who has played a million hands of poker is more skilled than the guy who played one.
By analogy, how good at this can any of us really be?
We'd all definitely be better at life if we had a few more tries.
Late comment, just had been mulling it, wanted to park it somewhere.
 True score theory: http://www.socialresearchmethods.net/kb/truescor.php
 Investors might have incredible careers only to face allegations of survivorship bias. I had some anecdotal
source here but lost it over the last day of sleeping on this. Sorry. Here's a wikipedia page? https://en.wikipedia.org/wiki/Survivorship_bias