Live in the United Kingdom. Go through your day working a boring job in a life that isn't very exciting. Meet an interesting man.
You learn that he's an alien with two hearts, flies around in a police box spaceship called a TARDIS, and is very lonely. You marvel at how the TARDIS is bigger on the inside. His name is the Doctor. He's a Time Lord from the planet Gallifrey; the last of his kind. And he owns a sonic screwdriver.
You start to fancy him. An infatuation really. Go with him in his TARDIS and fly around for a bit. Go see different planets and weird looking people. Land on the moon and see a Judoon platoon.
Did the Doctor mention that he can travel in all of time and space? Did he mention that you can’t cross your own timeline, you can’t interfere with the past, and that he couldn’t meet any of his former selves? It’s happened before and it will happen again, whether he says it can’t or not.
He calls you his companion and it makes you smile. You think that your life has finally gotten exciting. It most certainly has. But you almost die. First with the Daleks. Then with the Cybermen. Then with the Weeping Angels. The list goes on. Because you're with the Doctor, your life is in constant danger because of all his enemies.
You do a lot of running from anything and everything. Especially if you hear four knocks that are unrecognizable. You realize he can get very angry at the Universe sometimes and that some people would call him dangerous. But you don't care.
He once became your imaginary friend and you’ve fixed his bow-tie. In all your travels with the Doctor, you never once felt threatened by him. You’ve nearly died numerous times. But you wouldn't have it any other way.