5. His Long History Of Companion Loss
It's fair to say our beloved Time Lord goes through companions quicker than the Daleks go through world domination schemes but why does it always seem that as fans are finally getting to know these people, they just as soon leave? The companion(s) of the Doctor are his closest friends and they're typically the first to know his secret that he isn't actually human at all. His companions often serve as his conscience and stop him from making rash decisions and, while there were many times the Doctor has sacrificed himself for his companion (The Caves of Androzani, The Parting of the Ways, and The End of Time, to name a few), it's usually the companion who has made the sacrifice (à la The Traitors, The Destruction of Time, Earthshock and Voyage of the Damned). Doctor Who is nothing at all if not about loss and at the inception of the revived series, the Doctor was facing the ultimate one - the loss of his kind. As such, he - and us - believed for the better part of 7 series that he was the last Time Lord in existence (barring a few stragglers) and, what's more, that he was directly responsible for their death. New viewers could find themselves wondering how someone they just met in 2005 could have travelled with that many other people, without knowing he had been around for nearly 40 years (on television at least) by that time. And although the Doctor has had many companions, there was one event recently that must have left many new viewers scratching their heads...