That doesn't surprise me at all, Violet, because a very small minority of people are trans and many will go through life without knowing one, or knowingly so. There are areas where there are more visible trans people around, which is quite natural because people always try to live where there are others like them, however most of the time we only see on television or read about them.
In some big cities/towns in other countries there are transsexual and transvestite communities, Ibiza Town is one and has been so for many decades, and Brazil. I've no doubt there are pockets in London.
I'm a Londoner and long retired but when I was at work in central London I came across a couple of transwomen; at that time people would notice and whisper, mainly curiosity, not nasty so I was told about them before meeting (it was mainly curiosity, not nasty; the gender reassignment clinic at the Charing Cross Hospital was a fairly new thing then (I worked for the NHS), but I didn't gossip about them or behave any differently towards. There was a programme on TV in the 1990s about Julia, a transwoman, which many watched; she went through an awful lot and moved to Spain where she opened a small hotel. She is now dead poor soul. Her journey was extremely moving and interesting, quite an eye opener. Then in drama there was the story of Roy and Hayley Cropper in Coronation Street, Hayley being a transwoman, and we all loved Hayley.
Other than what I've mentioned, I haven't known any trans people and don't now. I was told by a friend many years back that a girl with whom we had been at school in the 1960s was undergoing gender assignment.
The media make a huge thing out of it and overuse of 'they' and 'them' is widespread but there are not many and never will be. However people do have genuine concerns which I share, eg about use of public lavatories ('rest rooms' in America), and changing rooms, because of a few things that have happened in places like prison. I 'get' that but at the same time I know there are always opportunist sex offenders, regardless of gender. The majority of trans people just want to get on with their lives, the same as anyone else. I believe we should live and let live.
In time I think all of it will die down, most will accept that there are transgender people, always have been, and there will be less media 'hooha' about the subject. There will still be male and female toilets in public places and office blocks, with a couple of unisex toilets for anyone to use. There will be less inappropriate use of gender neutral pronouns but we will call trans people by their chosen gender pronoun, whilst recognising that nobody can change biological sex.