Totally agree with you. And yes, I feel like I'm being judged too. And in a sense, it could be true since most people don't like it when someone who was not originally a part of the conversation just randomly joins in. I usually wait to be invited if I was not already a part of one and unless I am already a part of one, I am almost never invited. At most, and even this is rare, but if I'm close by to a group of people talking, they may briefly ask me a question if they were talking about something they weren't sure of but knew that I could possibly know an answer. But that is just very briefly.