Nowadays The Doctor is thought of as being mentally ill. At least Amy Pond thought he was. Famously, this is the exchange that got us all thinking right at the end of The Eleventh Hour:
Amy Pond: I thought...well, I started to think you were just a mad man with a box.
The Doctor: Amy Pond, there's something you better understand about me 'cause it's important and one day your life may depend on it...I am definitely a mad man with a box. Some say that anyone who declares himself mad generally isn't. Others that madness is itself merely a myth. All I know is that after 50-years the evidence is stacking up against our favourite Time Lord...
10. Geronimo!
Anyone prepared to fly a ship into the heart of a burning star / TARDIS, expecting only to end up being written out of history is clearly nuts. Actually, every time he uses that word he might as well wave a great big flag with, "Here's the loon!" plastered across it. He most recently uttered the immortal battle-cry in Asylum Of The Daleks whilst hurling himself from a spaceship onto a planet many miles below. And that's not the worst of it. Such as most other mad men across the ages have successfully done, he gets others to join in with the hysteria; on the Asylum occasion it was Amy and Rory. Now, I don't really want to have to put the good Doctor into the same bracket as Caligula, King George III, Spanish Queen Regent Joanna I, and the Emperor Nero; however, they did have in common with him the ability to inspire people to come along with them on their mad quests. How appropriate was it that he was on his way to an asylum, I wonder? The word 'Geronimo!' shouted enthusiastically does not represent a coherent argument for doing something insane.