The exception here, of course, is if you're at the wedding for the lead singer of Rage Against the Machine. In 1997.
Flash mobs of any kind
What's your endgame here, feeling like it's 2009 again, or landing a guest spot on Ellen during a particularly slow summer week?
Starting a political argument
This is not the place for everyone to hear your incisive thoughts on Bernie Sanders. Also, you've been posting them every day on Facebook for the last five months so everyone kinda gets it already.
That dumb necktie-around-the-head thing
"Yeah, the wedding was kinda underwhelming for a while, until motherfucking Chet took off his necktie and tied it around his head when 'Brick House' came on. After that, it was ON." Said no one ever.