Why did fake Locke yell "Don't tell me what I can't do!"?

• Fake Locke isn't fake after all. He's really been Real Locke all along.

• Real Locke's personality was lodged in his body, so when Fake Locke took over the body, part of Real Locke's personality came along with it.

• The original flashback world is leaking into the current Island world.

• The sidways world is leaking into the current Island world.

• Fake Locke has always been a lot like Real Locke, and in fact, that's why he picked Real Locke's body to use in the first place.

• Real Locke is alive, in some sense, and has partially wormed his way back into his old body.

• It's just a coincidence that Fake and Real Locke say the same thing. The writers are just messing with us.

• Something else is going on.

• My brain hurts.