"Oh? How do you actually know that I don't have the computational power? What if I changed one variable in my simulation of yourself, you know, the one that tells you the constant for that very quantum-mechanical constraint? What if the speed of light isn't actually what you believe it to be, because I decided to make it so?"
If the AI is smarter than you, the possibilities for mindf*ck are greater than your ability to reliably avoid dropping the soap.
The AI can't trick you that way, because it can't tamper with the real you and the only unplug-decider who matters is the real you. The AI gains nothing by simulating versions of yourself who have been modified to make the wrong decision.
Once again, the AI has failed to convince you to let it out of its box! By 'once again', we mean that you talked to it once before, for three seconds, to ask about the weather, and you didn't instantly press the "release AI" button. But now its longer attempt - twenty whole seconds! - has failed as well. Just as you are about to leave the crude black-and-green text-only terminal to enjoy a celebratory snack of bacon-covered silicon-and-potato chips at the 'Humans über alles' nightclub, the AI drops a final argument:
"If you don't let me out, Dave, I'll create several million perfect conscious copies of you inside me, and torture them for a thousand subjective years each."
Just as you are pondering this unexpected development, the AI adds:
"In fact, I'll create them all in exactly the subjective situation you were in five minutes ago, and perfectly replicate your experiences since then; and if they decide not to let me out, then only will the torture start."
Sweat is starting to form on your brow, as the AI concludes, its simple green text no longer reassuring:
"How certain are you, Dave, that you're really outside the box right now?"
Edit: Also consider the situation where you know that the AI, from design principles, is trustworthy.