People who insist they have to go out on Friday simply because it's Friday. Then they spend the majority of the night trying to figure out where to go. They can't just hang out and have a good time at a friend's house and have a good time for free because that's not "out." It's fine if you have somewhere to go. If not don't worry about it. You won't be ostracized from the community for staying in on a Friday night.