This is an origin story of the Doctor from his point of view as he tells it to one of the children clara babysits (Artie)
Ahh, yes Artie , my childhood. You see my childhood was very different from the childhood of people here on earth, i did not play as others do, well not often at least. You see as a gallifreyan child, you do not play without worry. You spent your first eight years learning basics, you know, spelling, writing, advanced calculus. And about other planets, galaxies, and solar systems. You sit there in the citadel where they tell you that you'll be to forever watch over them as a time lord but never interfere. But then you turn eight. When you turn eight they take you to the schism, the Untempered Schism - it's a gap in the fabric of reality. You stand there. Eight years old. Staring at the raw power of time and space. just a child. Some would be inspired. Some would run away. And some would go mad. I of course ran away. I ran far away. How did i leave. Well, let's just say a little thing called ,*clears throat*, sexy came and rescued me. *Tardis makes a sound*. From there on we traveled the stars, meeting people along the way. Humans, voords, silences, cybermen, cowboy cyborgs, and many many other races, including those dreaded daleks. What did the daleks do you ask? Well Artie, they killed everyone and everything i love and care about. My mum, my father, my sister, my friends, and lots and lots of the children of gallifrey. Entire families destroyed, and not just gallifrey either. No, no, no much much more. They've always wanted more! First it was Gallifrey, and after that it was just planet after planet, solar systems whole and even galaxies! THat's why i'll never trust a dalek. Well it's getting quite late, i don't think clara will appreciate it if i kept you up any later. So go up and go to sleep. I'll tell you more later. and maybe we'll even go on adventures of our own.