>
All of them?"~all" stands for approximately all, but maybe this mnemonic is less known than I thought. I'll try to avoid using it in the future.
> I know there are many discoveries that fit the pattern you're pointing out, but I wouldn't go as far as to say all I wouldn't go as far as to say all, or even the majority of them do.
I'm yet to encounter one that does not fit this pattern. As far as I can recall, for every discovery I've learned about, eventually[0] I've also learned it was made independently by others within few years; in some cases, the well-known case wasn't even the first of many, just the one that coined the name for some reason. Politics, geography, better formulation, better promotion, etc.
Related, but not the same - I'm also yet to encounter a discovery that took a great conceptual leap to arrive at. In every case I can think of, the core insight was quite obvious once enough prerequisite information was available[1], and pretty much happened on schedule. Sometimes the same person was involved in discovering the last missing pieces and then connecting them, but that's still a case of research being iterative.
It goes beyond science, too. You've probably seen Burke's Connections[2] (if not, I very strongly recommend it); it demonstrates clearly that technological advancement only happens[3] when all necessary pieces are there: scientific knowledge, necessary technology and right socioeconomic conditions.
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[0] - Sometimes it would be immediately, like in my teenage years, when reading a book about some mathematicians that went into the drama of who stole who's proof or took credit for the others' work (quite dramatic that book was). Sometimes it would be later on - years, even a decade later - when a book or a Wikipedia article about some breakthrough gave me more historical context than I expected. I eventually noticed the pattern; since then, I sometimes search for extra context immediately upon learning something.
[1] - Hindsight is 20/20, I know.
[2] - https://en.wikipedia.org/wiki/Connections_(British_TV_series...
[3] - I.e. actually sticks around - think steam engine in ancient Rome vs. Industrial Revolution.