I mentioned, in what must have been my first post, how if you peel away enough layers, plots of vastly different stories can be considered exactly the same. That's what happens when you reduce things to vagaries like "Man vs. himself" and "Man vs. Man." I mean, Cujo and Moby Dick are both "Man vs. the natural" but they're in no way similar when you look at everything else that makes them up.
Actual similarities aren't watered down phrases; they're when you look at something and see commonalities glaring off the surface. Sometimes it's called plagiarism, sometimes unoriginality and sometimes you have to chalk it up to coincidence.
I really don't like those "only six original plots." That in itself is unoriginal, plus it's usually only barely true enough to be called accurate. If you give two people the same idea, they're going to go running in different directions with it. Our selves are the sum of our external and internal experiences, and no two people have identical experiences. Perhaps tellingly, not even identical twins have DNA 100% exact. It's like 99.7 but it still goes to show you how nature's clones really aren't.
No two stories are ever alike. Rewrite another author's story sometime, as a writing exercise for yourself. Compare it to the original and you'll see all the things that makes you you, tucked away between the verbs and the nouns. I bet if you did it again ten years later, you'd come up with something very different from your first attempt!
That is life. That is writing. That is being special.
And go sign up for my contest, damn it. I'm extending it until Christmas Eve. Do it. Svengali commands it!