Back in the original series, the Doctor would land and immediately be put in prison for trespassing. When youve got six episodes to get through, a good old fashioned prison break is a nice way of padding it out, you see. With the revival in 2005, Russell T Davis gave us an easy way around this age old problem. Psychic paper that shows someone whatever you want them to see. Need ID? Need a stage pass? Need an Oyster Card? The psychic papers got it covered. It's only slightly psychic, though, and doesn't actually work on everyone. The very clever (such as William Shakespeare) and the not very clever saw nothing but the blank piece of paper. That being said, some Doctors never needed the psychic paper. The Seventh managed to weasel his way into an army barracks by fooling them into thinking he was important, writing his own letter of recommendation and signing it with two pens (in front of the very people he was fooling)! But with the paper in his pocket, the Doctor is less likely to be spending time handcuffed in dungeons. Many fans liked a lot of the Doctors antics as he proved himself to those around him and slowly gained their trust. It was part of who he was - someone who could win people over. But with only 45 minutes to save the world, some narrative sacrifices must be made.