I didn't finish my dress until about three days before my wedding - I had the flu and was stitching it from my bed. And the tulle came back from India all brown. We had to wash it for hours but that didn't dissuade me from wearing it.
I think in a way you're doomed once you can envision something. You're sort of doomed to make it happen. I've found that the moment I can envision leaving a relationship that's usually the moment that the relationship starts to fall apart.