I am looking for a single word similar to a turn of events, changing one's stars/destiny, passing a crossroads or doing something that would cause someone's life to have a dramatic change. From a writing perspective it is similar to a "plot twist" except happening to a person, if that makes sense. It does not have to necessarily be a catastrophic change, which for example happened as a result of guilt or a loss, but a change which sets a person on a very different path.
Eg.:
After that happened George's life would never be the same; he'd
reached a/an ______________ .
Best Answer
The term watershed is often used for this. From Cambridge Dictionaries:
The origin of its figurative usage appears to be from the geological term, where a ridge or other geological feature separates flowing water into different drainage systems. Thus the metaphor is very similar to a crossroads or fork in the road, but perhaps with less implication of a choice of path (the water doesn't choose which way to go, just like "history" didn't choose in the example above).
So for your example
would especially make sense if the event "that happened" was not of George's choosing or possibly if George did not foresee the consequences. You could also say that
or, even more simply,
Note that a watershed can be good or bad, both in the causal event and in consequences.