Invisible - I think the perception of being an outsider can be just that - perception. As a threadstarter, and regular "known" poster, I guess I feel like an insider, but I also find I make comments or ask questions that get no response. My point is that everyone gets ignored at times - the thread just moves on, or someone reads what you say but doesn't have anything to add. If you keep contributing thoughts about The Archers, then you are an insider - because at the end of the day, that's the only topic that we have in common.
What was the other point Ddd? Er, well, imagine you were a Cambridge graduate who really didn't make a point of bringing it up in conversation, and someone then said "Oxbridge types will always bring it up in conversation", then your paradox is that if you reply "well, I don't bring it up in conversation" you're proving their point. 