Anomaly
It wasn't her treatment to be out of the ordinary. She was.
Just like the others, you trapped her in a prison of shapes. Plain squares and dots and circles, not varying, just rearranged. For her, you laid out a path like any other – what set her apart was the way she crossed it.
She made for the end in the cleanest line you had seen. In fact, everything she did – up to that sweeping mess – she did with deadly precision. How great the havoc she wreaked would be, you couldn't have expected.
To be fair, you should have. She was human – they all were. She was just, so to say, a little more persistent than the average.
She was human, and her nature allowed no exceptions. She, too, had been born to spread chaos. She crashed through your mathematics like a wave of anomalies, bending strokes, changing courses.
On her own, she tore your geometry apart.
Now that she is gone, you fix it at your best. You can afford it. It took you years of patience to get rid of the stray lines – you erased chipped tiles, spiraling vines, aberrant curves and angles of all sorts.
Such is the task of the simplest computers. You correct calculations, and right wrongs. But the walls she destroyed, forever changing your outlook on life, weren't just the ones on the outside.
It isn't like you don't try to fix yourself. You predict the parts she took away, relentlessly, using the laws you always abode to.
No matter how many times you start over, the damage stays.
Even now, if you linger too long, you can feel the imperfections she carved within you. You touch them with your mind, one by one. They hurt – but they don't budge.
No big deal, then, you fiercely tell yourself. You are not the living mistake she used to be. You reign on the structure of this place.
Wherever you cannot, Aperture will be perfect in your stead.