Who knows me? or rather, who thinks they know me?

There are a few, of course. Family and friends, several of whom have known me all my life, and I have friends who have known me for over 50 years although, unfortunately, these are growing fewer as the years pass. These people know me and remain close.
How long does it take to really know someone? Some people are so open, right from the start, that you know you can trust them. Some, soon after you meet do something that is worrying. Sometimes it is just a case of being two different poles of a magnet.
 I recall an event, years ago, when a friend said to me 'oh, you must meet so-and-so. She's great fun.' And when the two of us met we had absolutely nothing in common. So there I was, trying to find common ground between us while she sat, almost speechless -  and we both knew - we could never be friends. There was just nothing recognizable between us.
Another time it was something as simple as the shoes someone was wearing. Don't laugh. I know it sounds strange but anyone who puts out one personna by their dress and manner and then chooses shoes that tell another story is definitely suspicious. And so it was proved a week later when they were caught in some dishonesty.
Growing up in a big city - in my case London - one finds one sometimes has to make pretty quick judgements on new people you meet - and as I aged I honed my intuition or judgement and found it was pretty good because those people I was forced, through circumstances, to meet during my life and engage with  proved, more often than not, that my judgement was right. They were either trustworthy or they were not.
How do I do it? Well it is not entirely intuition on my part - if at all. It is usually something the other person does that causes me to question - I then  pause momentarily before giving them  the benefit of the doubt. Perhaps I was wrong - so I wait and see while keeping that momentary reservation in the back of mind until it disappears. Usually it doesn't.
This was not something which came to me overnight or when I was young, it came over years.
So, if I'm a bit reserved with you - sorry - but perhaps I judged you correctly.  Or perhaps I am still waiting.