Where Do You Start?

Warning: this is not related to bicycling in any way or form.
If you came here hoping to read something about bicycling, move along, there's nothing to see.
So anyways, I was sitting here, staring at my tuna sandwich when I suddenly occurred to my OCD brain that I always eat my sandwich in a particular way.
Said tuna sandwich:



I pick it up in the usual fashion, right side up.
I mean bread is directional don't you know.



This does not include sandwich bread, that square looking stuff good only for toast.
So I pick up my sandwich, right side up.
Wait.
Don't forget the chips:



Just before I take a bite, I turn the sandwich, mostly in a clockwise direction though sometimes counter clockwise and eyeball the bottom left corner.
Just to clarify, let's look at the sandwich as sort of a Cartesian graph:



The corner about to be devoured would be the one in quadrant III.
Sometimes quadrant IV, but mostly III.
Why this is, why I feel compelled to take a chunk not from the top, but from the bottom, I have no hypothesis.
There should be a good explanation for this is not a random act.
I believe it has been going on for years, though I have no proof, the evidence has been digested long ago.
As regards to the next bite, I need to gather more evidence.
I believe I work on the said sandwich in a counter clockwise direction, taking bites out of the outer portions, though I believe it depends largely on how I happened to replace the sandwich on the plate.
Today it was counter clockwise:



I'd call that a bite out of the Y axis.
Now it's more or less random, I'm concentrating on choosing just the right potato chip:



The shape of the chip does not matter, it must be just the right size.
This becomes a problem for the size of the chip seems to be proportional to the amount of chips left in the bag.
Still I persevere until nothing is left of said sandwich but the center:



Plotted on the Cartesian graph, that would include an area roughly the size of a rectangle with the following coordinates: (3,5)(-3,5)(-3,-5)(3,-5)
At this time, the bites are purely random for it is difficult if not impossible to discern top from bottom.
Once the sandwich has been ingested, this may be followed by more chips, this time the size is not important.
The procedure for a turkey sandwich is similar:



The only difference being the pickle must be carefully rationed so as to last until the sandwich is finished.
Having a little leftover pickle is okay too.
If you know what I mean.