One more kick in the rear from my man, Ray Bradbury, from his amazing Zen in the Art of Writing:
"Remember: Plot is no more than footprints left in the snow after your characters have run by one their way to incredible destinations. Plot is observed after the fact rather than before. It cannot precede action. It is the chart that remains when an action is through. That is all Plot ever should be. It is human desire let run, running, and reaching a goal. It cannot be mechanical. It can only be dynamic."