Decisions decisions decisions... one word, a single, simple, silly little innocent word. Decisions... This, or that? Left, or right? One slice of cake, or two?
Decisions... the most commonplace thing in the universe, one literally runs into a decision every three or four seconds. Do I stop walking, or do I take another step? Do I breathe out, or do I breathe in? Do I smile, do I frown, do I pout, do I glare, do I grin, do I laugh, do I cry, do I feel?
So many decisions, so many choices. It's enough to give one a headache, it is. Some people believe that every time a choice is made, an alternate universe is created in which the other decision had been made. Personally, he thought that was rubbish. If it were true, there would be too many alternate universes to count, there would be more alternate universes than there would be grains of sand on every beach and every desert on every planet in every galaxy in all of these unending infernal alternate universes.
Not to say that there aren't alternate universes, he'd been to enough to know that there are. But Usually, an alternate universe is created only when the decision made is significant enough to cause a drastic change. For there to be an alternate universe for every time someone chooses to pour cereal into a tupperware container instead of washing a cereal bowl would simply be way too problematic and complicated.
But for a man like the Doctor, every decision is a drastic change in the timeline continuum. That's why Time Lords weren't supposed to meddle.
Meddle... such a funny word. Such a single, simple, silly little innocent word, one that has a very strange and dangerous connection to the word decisions. To meddle is to decide to manipulate events and peoples into a future you believe you can shape, and to decide is to meddle in the universes' idea of what is to take place. You decide to meddle, and to meddle is to decide.
Meddle, Decisions, and Time. What could possibly go wrong when those three unusually powerful words are thrust into the hands of a man, one man, the last of many, who had already before Decided to Meddle with Time? He had proven two things to himself: He was not as omnipotent as he had thought, and fixed times were never truly fixed if they were handled right.
Fixed times. Times that had to happen, times that couldn't not happen, that could never not happen. So complicated. Like he had once said, a big ball of wibbly wobbly timey wimey stuff. Pull so much as a single thread of timey wimey out of the wibbly wobbly, the whole thing could theoretically collapse in upon itself, and the resulting implosion/explosion/corrosion/erosion would be enough to destroy and blot out every single thing. He'd seen that before, too.
So, a recap: A man who is decidedly not omnipotent who meddles and decides, who can meddle with time and can decide to meddle, who meddles with decisions and times to decide, and decides to time his meddlement.
Confused? Don't worry, it's all part of that wibbly wobbly I mentioned earlier, which is, to say the least, complicated.
And what does this have to do with alternate universes, you ask? Well, that's easy. One day, a man will make a decision to meddle with time, throwing caution to the wind, and this shall create the biggest, most spectacular, theoretically threatening universe imploding thought processing alternate universe ever to be shown through the untempered schism.
This is the final adventure, this is the last stage, this is the decision that ultimately ends up ending all ends at the end of endings.
Still confused? Perhaps the alternate title shall clear things up:
The Day the Doctor Stopped Susan.