Danny Pink's role in Series 8 as the boyfriend-back-on-Earth of the Doctor's companion was nothing new as, way back in 2005, Rose's sort of other half mechanic Mickey Smith was left behind when she went to see the stars in the TARDIS. The Doctor may have not thought much of him - calling him 'Mickey the idiot' - but underneath this largely comic relief character was a much more mature and capable person. He helped them save the world numerous times and eventually he became a companion in his own right when he joined the Tenth Doctor and Rose on their travels. Mickey's time in the TARDIS didn't last long, however. Realising that he did not want to be a third wheel in their relationship, he elected to stay behind in a parallel Earth to defeat the Cybermen. Finally over Rose, Mickey went on to become an ace alien fighter and, after returning to our universe, married another of the Doctor's companions, Martha. Not bad for an idiot.
