I hear your brother. Some unsolicited advice regarding loud clubs: They're pretty terrible places to talk to girls, as you said. They're also stellar at making you feel deficient if you feel like you're supposed to be there for something other than the music. But they can be fun if you dance your ass off. Certainly a little liquid courage makes that easier, but this semester I've been sober and I've still gone out a few nights just to dance around. The liberating knowledge with clubs, as in many incomprehensible social scenarios, is that no one really cares what you're doing, how you look as you dance, as long as you're enjoying yourself. Do you like loud dance music? If so, clubs might be for you. But you might just not like loud music, or the particular DJ. But when the music isn't scratching your itch and you're watching other people have the time of their lives, that's a recipe for a sad walk home.
Douchebaggery is often the result of the bravado necessary to power through both parties' fundamental instincts to keep to themselves. The real question is: can they turn it off? Because the ability to act like a douchebag without becoming a douchebag can be useful in the first few hours of relationships. The ability to not be a douchebag is what keeps them going.