I thought the phrase was a whimsical/poetic way of saying something that rings true to me: that all the possibilities in your mind get narrowed down to a single imperfect one when actually materializing/putting them into practice -- in a way getting "destroyed" and replaced with an imperfect but existing version -- and that we sometimes get anxious about this.

It's not the only way of looking at it, but it is one way, and it's not wrong.