Why are some people so simple?

I live with four people, this one girl I live with is very simple. I mean we get on well, but when it comes to thinking outside the box she has nothing, no quality, she's a complete lack of common sense, we're all students. She got better grades than me at A level A's all round, now we're at University. I could never figure it out because she is a simpleton, she watches crap like the only way is essex and geordie shore and loves it, I passionately hate it. She never talks about politics or economics because she knows nothing about the real world, only her bubble of a life, for me, education is not a great way of measuring true intellectual capacity, my lecturer even said it, "education is typically about us shovelling sh*t in, and when it comes to exams you throwing up the same sh*t out". I just think that as members of this society we should take an interest in real world affairs, things that very much affect our lives, she didn't even know who she voted for and then said she voted for Labour only because her mother did too, I mean come on it's just ridiculous. Effectively she's brain dead to the real world, and would rather take an interest in and glorify these fake wannabe celebrities because they're from the same place as her, essex.