Progressive metal is a generally needlessly complicated and unstructured form of music that often makes minimal sense to the majority of metal fans because it can only be appreciated by people with an IQ over 600.
Progressive metal fans often believe they are superior to any fan of any other genre and will generally reject any piece music that isn't at least 20 minutes long with 40 key changes per minute.
Music in 4/4 is like kryptonite to a progressive metal fan and they must be administered dream theatre riffs as an antidote
An easy way to spot a progressive metal fan is to look for the guy who is pissed off at Opeth for dropping the growls yet goes to their shows anyway and yells for them to play Black Rose Immortal. He will also let everyone know that he's mostly there for the support band, who he has known about for ages.
In short, the math nerd of metal
*At an Opeth show*
Friend: Who's that guy *Points at a guy middle aged guy with long hair, glasses and a dream theatre shirt on stood in the middle of the pit looking like a moody teenager*
Me: Oh that's a progressive metal guy, he actually hates this band because their music is too simple
Friend: So why's he here if he hates them?
Me: Oh it's happening, look at him now
Prog metal guy: I HATE YOU GUYS WHY CAN'T YOU JUST GO BACK TO THE WAY YOU WERE YOU BETTER PLAY BLACK ROSE IMMORTAL RIGHT NOW OR I'M OUT OF HERE.
Friend: Wow
A foreign language used by gay autistic kids to ask for some food.
Autistic Kid: "Oh my! Spare Sausage? May I have some?"
Other Autistic Kid: "Of course, take some sause too.