"Persons attempting to find a motive in this narrative will be prosecuted; persons attempting to find a moral in it will be banished; persons attempting to find a plot in it will be shot."
Huckleberry Finn intronote
"Hughes' Zeroth Law of Geekhood states: "Never put more effort into analysing a creative work than its creator(s) put into creating it."
There are three ways of dealing with time travel in Doctor Who (you might want to print this out for future use.)
1. Look, it's just a story, time travel is completely impossible, the whole thing's a farrago of lies, ooh, look at those monsters.
2. Time can only sometimes be rewritten, and the Doctor has a vast and terrible Time Brain that allows him to see when events can be altered and when they are fixed, but for us mere mortals, such insight would turn our brains to soup, ooh, look at those monsters.
3. Ooh, look at those monsters!
I like 3. It's quicker.
"...but still, if we are to believe the history of Don Quixote that has come out here lately with general applause, it is to be inferred from it, if I mistake not, that you never saw the lady Dulcinea, and that the said lady is nothing in the world but an imaginary lady, one that you yourself begot and gave birth to in your brain, and adorned with whatever charms and perfections you chose."
"There is a good deal to be said on that point," said Don Quixote; "God knows whether there be any Dulcinea or not in the world, or whether she is imaginary or not imaginary; these are things the proof of which must not be pushed to extreme lengths. I have not begotten nor given birth to my lady, though I behold her as she needs must be, a lady who contains in herself all the qualities to make her famous throughout the world, beautiful without blemish, dignified without haughtiness, tender and yet modest, gracious from courtesy and courteous from good breeding, and lastly, of exalted lineage, because beauty shines forth and excels with a higher degree of perfection upon good blood than in the fair of lowly birth."
Don Quixote, Part II, Chapter XXXIInote