I went to a nightclub with my friend for my 18th birthday...it turned out to be a gay club. Nobody was a dick so when he asked me to go again I went (he turned out to be gay). I hate the scene though, and refused to go again the next time he asked. It's loud, inescapable noise from the time you enter to the time you leave, you get the sweat (and more) of a million strange and dirty people on you, I came out smelling like beer and cigarettes (which I HATE, because I always feel stale and non-existant when I smell like this), it's dark and more often than not they've put up strobe lights, which makes it extremely difficult for me to navigate or really know where I am even in a one room club...plus it's a false friendliness amongst other club hoppers that I can't stand. They're either overly nice and "fun" (not my definition) because they are extremely high, and you have how much of reality they actually still have a grasp on, or because they're looking to get laid, or because they're just so pumped up on adrenaline (also "high", I guess) and excited about being out dancing and yelling and all that, that they're friendly in a non-meaningful way (the way you might actually be nice to someone you hate right after getting a new puppy, per se).
Basically, clubs are loud, disorienting, smelly, and everything is artificial.