I may have to put on my tin hat and hide behind the sofa, but I sincerely hope not as this is a genuine question.
Would you say that you actually challenge your thinking and if so, would say that your views are evolving because of it?
Let me give you an example: in my much younger days, I was married to a member of the armed forces, I read only the newspaper that he bought and listened to people (primarily his friends) whose views mainly mirrored his. I didn't expose myself very much, certainly not deliberately, to contrary views and yet at the time I could have given a rationale for what I 'believed'.
Later I went to college and was exposed to a range of different views and I tried to teach myself to really 'listen' to others rather than react by 'defending' my own opinions and in doing so I found that my own thinking not only changed quite radically, but continued to evolve.
Now I read widely, I try very hard not to demonize others' points of view, I seek out the opinions of people who hold views that are antithetical to my own - and I try (not always with success) to find points of commonality or mutuality.
To think that London, or anywhere else for that matter, does not belong to any one demographic