Bridie22
We can surely see that somebody is nasty, has a cruel streak... our human instinct usually picks this up.
You obviously haven't had dealings with a narc.
If you are the child of a narc, you are quite used to their behaviour because they are the only way you have ever known. You lack self esteem because of the way they have treated you so you think it must be your fault. In my case, that affected all my relationships from a young age because I didn't know what a normal relationship was. I was also frightened of my Mum. She had ruled my life with violence, moods that swung between me being a wonderful daughter to out of the blue me being the worst daughter anybody could ever had. It was just so confusing. Oh and the constant message that there was something very wrong with a person who abandoned their mother who should be the most important person in your life. This was so imprinted on to me that it took me years and a very kind, thoughtful man to help me see that my Mum's behaviour was toxic.
Narcs don't start off being cruel if they are love relationships. As new boyfriends, they are often charming and make you feel so loved because there is no one else in the world they'd rather been with. You look at that as being the pattern of your relationship so when things start to change, you are perhaps more forgiving than you might normally be. Their digs are often subtle to start with too. Just enough to make you start to doubt yourself. If you have also had a parent with similar traits, you are so used to this behaviour it is almost normal. You are used to being unhappy, it's just the way things are.
I can only see this now as I have distanced myself from such behaviour. I am not a stupid person, just someone who didn't know there was a different way to have a relationship with someone.