Doctor, I Let You Go
"You wait a moment, Doctor. Let's get it right. I've got a few things to say to you," he says just before he sets to work regenerating. Regeneration is a tricky business and the Twelfth Doctor almost didn't regeneration but during the Doctor Who Christmas Special, "Twice Upon a Time," he acknowledged that humans needed him. He decided that he would regenerate, and this time he'd get it right. Here's hoping that the Thirteenth Doctor doesn't make the mistake of eating pears.
The Doctor doesn't like endings, so it's no surprise that a future version of himself would save River Song's life after witnessing her death in The Library. At the end of Doctor Who Season 4 Episode 9, "Forest of the Dead," the Doctor saves River's consciousness. In a computer's virtual world, inhabited by an AI, and the consciousness of a young girl, River is able to live out her days, but still tells stories of the Doctor and his amazing feats. She reads to the children at bedtime, "Now and then, every once in a very long while, every day in a million days, when the wind stands fair, and the Doctor comes to call. Everybody lives."
Missy Pleads for Her Life
The Doctor and his childhood friend, The Master, have always had a long and sorted history. That history came to a head on Doctor Who Season 10 Episode 6, "Extremis," when the Doctor was called to be Missy's executioner. The story is braided into a larger plot, and the audience never gets an answer for what Missy to warrant her death, but right before the Doctor pulls the lever she makes an emotional plea for her life. She says, "I know it doesn't. I know I'm going to die. I have to say it, the truth. Without hope. Without witness. Without reward. I am your friend."
Fear Makes Companions of Us All
Time travel makes for some very crazy circumstances. Like the time Clara ended up in a barn with a very young, and very scared version of The Doctor at the end of Doctor Who Season 8 Episode 4, "Listen." That is before he even was The Doctor. The boy in the barn is a scared child afraid of everything to come, but Clara knows his future and has a few kind words for him in regards to fear. "You're always going to be afraid. Even if you learn to hide it. Fear is like, a companion. A constant companion always there. But that's okay because fear can bring us together. Fear can bring you home," Clara tells him.
A Scale Model of War
"When you fire that first shot, no matter how right you feel, you have no idea who's going to die! You don't know whose children are going to scream and burn! How many hearts will be broken! How many lives shattered! How much blood will spill until everybody does until what they were always going to have to do from the very beginning! Sit down and talk!" screams the Doctor on Doctor Who Season 9 Episode 8, "The Zygon Inversion." In what might just be the best speech ever given on Doctor Who, the Twelfth Doctor gives a Zygon and the leader of U.N.I.T. a lesson in exactly what happens when you go to war! Consider The Doctor's history; he's the reason his home planet was destroyed in The Time War. If you should listen to anyone on this matter it's him.
We're All Stories in the End
Continuing on the theme of The Doctor being the most selfless alien you'll ever meet, we have his "We're All Stories in the End" speech from Doctor Who, Season 5 Episode 13, "The Big Bang." In an attempt to repair the cracks in the universe, the Doctor flies The Pandorica into the heart of an explosion and ends up watching a rewind of his life. During it, he tucks in a little Amelia Pond who had fallen asleep waiting for him in the garden. "When you wake up, you'll have a mum and dad, and you won't even remember me. Well, you'll remember me a little. I'll be a story in your head. But that's okay. We're all stories in the end. Just make it a good one, eh? Because it was, you know. It was the best," he begins.