wtf, why can't I watch it?

I find myself hemming and hawing over episodes 8 and 9 of Doctor Who, S4. Seriously. I've been waiting two weeks for this and I can't watch it. I'm so reluctant, it's not even funny.

Those two episodes are taunting my on my hard drive.

AND I CAN'T BRING MYSELF TO WATCH IT.

WHY????