lixabiz:

It’s the oldest story in the universe. This one or any other. Boy and girl fall in love, get separated by events – war, politics, accidents in time. She’s thrown out of the hex or he’s thrown into it. Since then they’ve been yearning for each other across time and space. Across dimensions. This isn’t a ghost story, it’s a love story.

When they made this particular hero, they didn’t give him a gun. They gave him a screwdriver to fix things. They didn’t give him a tank or a warship or an x-wing fighter—they gave him a box from which you can call for help. And they didn’t give him a superpower or pointy ears or a heat-ray—they gave him an extra HEART. They gave him two hearts! And that’s an extraordinary thing. There will never come a time when we don’t need a hero like the Doctor.”
Steven Moffat