I know this happens, I know I’ve had it happen to me a couple of times. Do you want to know the kicker? The members of the real-fan-inquisition…are not real fans. It’s mostly impostor syndrome talking, with legit reason. They are pretty much trying to solidify their own creds by ‘finding you out’. Immerse yourself in the geekdom and you will find a core that is welcoming and forgiving. They also tend to avoid the “I know everything” hostile types like the plague. These are the people who break out a smile instead of getting angry when you say “No, I said Sci-fi. Star Wars isn’t Sci-fi. It’s a fairy tale. Oh by the way, do you know what the Borg call a Deathstar? -Escape pod” They probably will still hit you with the dimensions of the Deathstar and the Borg Sphere, -but they’ll get the joke. And they much rather talk philosophy than trivia.
You don’t need to know the blood type of anyone to discuss what the walrus is.
The best move you can make at conventions is to look the guy interrogating you up and down and then wander off for a pleasant conversation with a real fan.
Also, saying Han shot first is suggesting Greedo got a shot off. It’s just wrong.