Yep, I have mastered the art of invisibility . In my case I think it was something I learnt to do as a child, in my unhappiness I was quite withdrawn. Now I am sometimes surprised to see myself fading again... But I've worked very hard to not let it affect my sense of valuing who I am.
I have learnt there are lots of reasons why people forget to pay attention to other people, and so I refuse to take it personally when it happens to me but I also work quite hard to really pay attention to the people that I do spend time with.