New trend?

So my boyfriend and I went to see Pearl Jam play at the Wachovia Center, and they were amazing... seriously, one of the best concerts I've ever been to. I don't think I've ever been to a show where the crowd was so amped for the entire duration of the show. It was so incredibly LOUD -- and not even from the music, but from the roar of the crowd. My ears are still ringing today. Yes, I am old.

Seriously, perhaps I am old. And bordering on unhip. Is wearing concert tees TO the actual concert now considered cool? Back in the day, you were so geeked out if you wore the t-shirt of the band you were going to see play, or if you bought one at the concert and immediately put it on. Is this not the case now? Someone needs to inform me so I can cling to my youth for just a bit longer.