We all have a moment in our life where something happens and that change the course of our life.

  • "A moment when... and that changes" etc. – Mark Hubbard Feb 18 '17 at 3:53
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    "where" is fine. When we think of life as a journey, then "where" evokes that sense of traveling along through life and so makes sense. Nevertheless it's a somewhat idiosyncratic usage. – A.Ellett Feb 18 '17 at 4:39

As I'm sure everyone here is aware, Einstein told us that we're living in a four-dimensional, smooth, connected Lorentzian manifold called spacetime, a combination of three dimensions of what we perceive as volumes of space and one dimension of what we perceive as unidirectional time. Our perceptions lead us to consider a moment as a point in time and a place as a point in space. And the Ngram viewer backs this up: writers prefer moment when to moment where by about thirty to one.

But English does accommodate the Einsteinian notion of a moment as a place in a metaphorical sense, perhaps involving abstractions such as emotions and personal relationships. Here is an excerpt from Temporality in Life As Seen Through Literature about the work of Virginia Woolf:

Woolf also refers to moments of pain, whether it is the moment where the presence of someone does not mean anything for us, to that moment where it is suffering to recall the inadequate character of human relations....

(internal references removed)

  • +1. As for smooth, are you ignoring gravity? – ab2 Feb 18 '17 at 21:31
  • @ab2 Smooth in this context means infinitely differentiable. I find that one ignores gravity at one's peril. – deadrat Feb 18 '17 at 21:40

"We all have a moment when something happens..." is correct because moment is a point in time, and when describes a point in time.

Where would describe a location, "We all have a place where we go..."

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