Mickey’s journey is one that I absolutely adore. He goes from cowering in complete fear near a police box, and clinging desperately to his girlfriend - to confidently standing up to the Daleks and parting with his new bff Big Scary Gun while defending all of reality. The young man who couldn’t imagine navigating London without Rose’s companionship decides to play a few rounds of universal musical chairs, living in a whole other world by himself.
And his relationship with the Doctor changes radically. At first, he yells at Rose that the Doctor’s “an alien! He’s..he’s a thing!” And the Doctor explicitly states that Mickey the Idiot isn’t invited into the TARDIS. But by series 4, he and the alien (who once thought Rose’s silly little boyfriend’s name was ‘Ricky’ - a stupid ape of a tin dog) gladly fist-bump like beloved frat brothers. I like to think that when Ten was dying, a glimpse at Mickey wasn’t just an added bonus to his Martha visit; Mr. Smith held immense importance all his own.
(Source: flapperorslapper, via dont-be-obvious)