There are a few things in my life that I buy cheap and often: chapstick, pens, sunglasses, and sippy cups--because they always disappear. I don't lose them. I'm much more responsible than that. They really do just disappear.
(Okay, I'm going to have to blame my children for the Case of the Missing Sippy Cups. I think I've purchased ten for my daughter in the last two months. And then there is my son, who although four, has decided he now likes sippy cups too.)
More frustrating that chapped lips when I just bought strawberry flavored chapstick or squint lines on my face which wouldn't be there if they would just stop selling me vanishing sunglasses! IS...
...the missing perfect idea or scene or plot arc or dialogue...
These first come to me in one of three places: just before I fall asleep, while driving, or in the shower. (You know-the unburdened and emptied mind equals inspiration.)
Sometimes, in fear of forgetfulness, I'll start stringing together unrelated (but oh so related) words. Which means I'll come home chanting "park bench, motorcycle, Jean Valjean" or "blue toothpaste, cheerleader, Indian."
Then, if I write it down...even if I manage to write it down moments after it strikes...it still goes missing somehow. It never exists as beautifully as it did in my mind. Or sometimes I'll just leave it there-in my mind. File it away for later, and hope it will just show its face again when my manuscript is ready for it.
What about you? How do you salvage that perfect moment in your story which plays oh so nicely in your head? How do you help yourself remember?