To say that Clara Oswald is an indifferent teacher at best would be an understatement. She has let her wards wander off without supervision, is more than just a bit flighty, had a relationship with a fellow teacher, and often disappears for indeterminate lengths of time. Logically, an instructor such as Clara should have been fired quite some time ago.

However, there may be a reason as to why Clara remains on staff at Coal Hill Secondary School, and it may have to do with the Doctor’s past. Remember back when Ian Chesterton and Barbara Wright, Susan’s teachers at Coal Hill, followed her back to the junkyard where she and the First Doctor were hiding out? Well, when they entered the TARDIS and became companions during the Doctor’s travels, naturally a relationship would have formed.

That relationship with the Doctor may have lasted longer than just those journeys. In fact, it may well be that the Doctor is why Clara Oswald not only is still employed at Coal Hill, but why she received her position in the first place.

During the 50th Anniversary Special, the sign for the Coal Hill Secondary School was pictured for a few moments. Those with sharp eyes, or those with a DVR who simply want to examine every aspect of everything, may have noticed a familiar name listed on that sign. See, Chesterman has, in the past fifty years, risen from being a science teacher to the rank of Chairman of the Governors. Essentially, if Chessman wants something or someone at the school, he would get it.

So, perhaps as a favor to his old friend, someone who allowed him to see far more of history than he could have ever imagined, Chesserson may have given Clara Oswald her position. He may be willing to overlook those flaws and her flightiness, recalling what it was like when he disappeared for two years with Barbara and coming up with the explanation that they were on a mission in Africa.

Yes, Clara Oswald may not be fit to be a teacher, and she may be everywhere else mentally. Yet, her friendship with the Doctor may be paying off in more than just her own adventures throughout time and space – it may be that another old friend of the Doctor’s, Ian Chesterson, is protecting her as well. It certainly helps to have friends in high places.