But I've got new ones!  I'm increasingly thinking that the notion of existence/non-existence are going to be critical.  In series 5, people kept getting wiped and forgotten, the universe was blown up (except for the Earth) presumably for some mysterious reason by the Silence, the Silence's main power seems to be that they can be wiped and forgotten?  Coincidence?  I think not.

They've spent thousand of years on Earth and what have they done?  Created a massive underground tunnel network with semi-TARDIS devices in it...  and the Earth was the planet at the center of all that "erasing the rest of the universe out of everyone's memories"  Coincidence?  I think not.

All these things existed and didn't exist at the same time.  Like Amy's on-again, off-again baby?

Rory, dead again in the Black Spot, and yet, alive against all likelihood.  What is that guy made of?  Plastic?