Who is Sifo-Dyas?
If you can't figure it out from starting here, here, here, and here, then I can't help you.
(note: most of these are to the *starts* of threads)

Ewoks & Gungans
I happen to like them. Very much. If you hate 'em fine, just don't diss me for my liking them. Mesa goin Yub Nub! :-)

What's a Duck?
The Queen's Decoy, Sabé! :-)

You use decoys when you don't want something to get shot. Sabé's job was to make sure Amidala didn't get shot. Throughout most of TPM we see Sabé in the get-up rather than Amidala. When you see the decoy more often than the duck, the decoy becomes the duck. Besides, isn't a duck decoy shaped like a duck and thus can be called a duck anyway? Aren't duck decoys usually made out of wood? Wasn't the decoy duck a bit wooden in personality? I shall go get my best scales...

Did the Stormtrooper hit his head?
No. He bumped his helmet against the door. The Stormtrooper didn't hit anything.