I have seen and experienced many interesting things within my group of friends and in the world or sci-fi conventions. Sometimes the descriptions of what happened and in some instances what I have turned down would be only seen by those who enter certain stores where my daughter would not be allowed. So a thing like seeing two people dressed as Buddy Christ boffing (battling using foam swords) at a con is not out of the ordinary and actually rather mild.
At a sci-fi convention in 2004 shortly after I started to really know people well, a question was posed within our group of about 15 people who is the most normal and it was unanimous that I was. I get a laugh out of people (and occasionally a worried look) who know me at work or within my family when I say that. Being older than many, having a kid, not being a true computer person (talented enough to find a job in that industry), straight, having little artistic or musical talent, and mostly a sports fan are the things that make me such.
It rarely causes conflict since I escape my normal world with fandom. I usually don't want to talk sports or anything within my life there. When I am at a con, I don't care about what happens in sports and have to catch up the Monday after.
One thing that a difference shows is literature. When I was in grade school, I would read books about science, math, or sports. I had no interest in stories and having a test about a novel every other Monday in high school was the most difficult academic thing I had to endure there. Except for a period in the mid 80s where I read every Dr Who novel I could find, I never cared for fiction. Since I got a full time job in late 1987, I have read two books and one because I made a promise to people who were awesome enough to throw me a surprise 42nd birthday party. At conventions and at my friend's houses I see a large number of novels. They read them, I don't.
I do watch movies and tv and my friends' interest in certain ones and music about them have made me watch them even if they were based on books I would neither have the time nor interest to read. Harry Potter is one of them. Though I am not interested in reading 7 books, I do have the time to invest to see movies and for me it is ok that the movie will not tell the whole story as written since 2 and 1/2 hours can't cover 700 pages of material. The two occasions where I saw a novel from high school turned into a movie, I was disappointed in how it was adapted and in the Natural, upset they changed the ending of the story.
I knew something significant happened at the end of the sixth HP book. Whenever people in the chat room started to talk about it, I would conveniently need to leave since I was going to find out when I saw the movie. On Tuesday at the FuMP (www.theFuMP.com) there was not only a song based about what happened in the movie but in the description was listed how it did along with a statement that everyone knows what happened in the movie just like the secret in Citizen Kane. I was pissed off. I posted a comment stating the people who have been working for the past 20+ years might not have the time to read books and someone else commented about the same thing.
I also found little agreement from those in the chat room since they by being younger and into literature, were able to read all the books and surprise from them that I never read any of the Lord of the Rings novels either. After reading the Hobbit as a Junior in high school, I would never consider reading LOTR.
Out of curiosity I asked 20 people who have a full time job if they knew about the ending to the sixth book:
The 5 percents cover one who correctly guessed at it, one who knew about it but was not sure in which book it happened and one who not only was able to answer the question but provided unsolicited detail about the explanation given in the seventh book.
16 of the 20 knew Rosebud was a sled.