Phrase for shared experience which indirectly affected direction of a field

Question

Imagine that every person who had gone on to do something extraordinary in a field of endeavor had had a shared experience --

E.g. imagine that every scientist who received the Nobel prize in 2015 had coincidentally been at the same summer camp in 1995 and seen a person give an amazing talk that inspired them all to be scientists. Or imagine all of the great musicians of the 1970s had been to Woodstock as teenagers.

What would you call this shared thing?

Bonus points: I'd love if there were also a sense in this phrase/word of a "crossroads" - that is, there was directionlessness and this event "cleared the way"

Answer 1

The word to describe the shared thing is "synchronistic," the adjectival form of the Jungian term of art "synchonicity." ("Synchronous" means something dfferent -- acting in lock step.) Carl Jung, the Swiss psychiatrist who founded the school of analytical psychology, believed that events that are unrelated causally can be related by meaning, which in your examples would be discovered only some time after the event in question. Since I don't read German, I'll have to take Ann Casement's translations in her book Who Owns Jung?:

Most succinctly he [Jung] defined it [synchronicity] as as "meaningful coincidence", as "acausal parallelism", or as an "acausal connecting principle". [inline citations removed]

I can't think of a single word that combines both the original shared event and the impetus the event gave the participants, but perhaps you could add a second adjective "galvanizing," meaning to induce to action, named after Luigi Galvani, the 18th century Italian scientist who discovered the electrical nature of muscle control.

Answer 2

You seem to be describing a watershed event.

Watershed

1. The entire region draining into a river, river system, or other body of water: a list of reptiles found in the watershed.
2. A ridge of high land dividing two areas that are drained by different river systems. Also called divide, water parting.
3. A critical point that marks a division or a change of course; a turning point: "a watershed in modern American history, a time that ... forever changed American social attitudes" (Robert Reinhold). TFD

It's not exactly a crossroads metaphor but people do navigate river systems.