Doth Mine Eyes Deceive Me?

"Or is that a foil to my genius hovering over my shoulder?" 

My Utopian Writing Spot. ;)

There comes a time in every writer's life when she is sitting at her keyboard and absolutely cannot write. Not because she has Writer's Block, not because she is physically impaired. No. Because she's met her Kryptonite. Or, as we old-fashioned people say, her Achilles' Heel.
For some it might come in the form of an empty spot where their mug of coffee usually abides.
For others it might have something to do with their nails being too long and clacking during the typing process which is most distracting.
Who knows? For some of you it could even be because you have the Broadway song, "Popular", stuck in your head and can't seem to make it go away. ;) But I can tell you what my Arch-nemesis is. What makes me cringe and puts a massive road-block in my brain? What is the worst impediment to my wit? What can cow me within a moment of its appearance? Ready for it? Okay, but I'm warning you, it's disturbing!

.....Someone reading over my shoulder.....

There! It's out and I feel muchly better. ;) Seriously, I could have a perfectly smashing idea banging against the sides of my brain to be let out onto paper or Microsoft Word or anything else, but the moment the face of an inquiring person peers over my shoulder, the Thing is effectively shut up in Jane Murdstone's metallic handbag, or locked in an airtight box, or strapped to The Rack. In essence it is Temporarily Destroyed.
I don't know what this People-Watching-Me phobia stems from, unless it be a creeping feeling that I am unequal to the task of transferring my thoughts into words. Or it could be the fact that during the writing process I am susceptible to every form of self-doubt, feeling silly for writing something mildly genius, or any number of other problems.
Whatever the case may be, I cannot write with someone's eyes on me. It bothers the dickens out of me [no pun intended. :P] and I have to get rid of the person ASAP if any progress is to be made. ;) The first method of warfare against Inquiring Minds begins with a cold stare at the computer screen, entirely ignoring the person. If that fails, I resort of tapping the keys loudly in an irritated sort of fashion. If that fails, I turn and stare at the Inquiring Mind and ask with cold civility, "What are you doing?" If this too fails I turn pointedly back to the computer screen or piece of paper and say, "You know I can't write with people watching me." And they usually leave without further protest.
I admit it. I am not an angel when genius burns. Not by any means. But it is partly the fault of the Inquiring Minds who, did they care to inquire into Memory's hall, would remember my aversion to being watched while scribbling. :D
What's you Achilles' Heel? And how do you get over it?