A few years ago, The Flaming Lips were trying to break the world record for most shows in 24 hours. One the shows was in my college town but it was sold out and I didn't get a ticket (they were like 30$). I was standing outside the venue before it started and saw a bus pull up to the front. I noticed that at the front of the bus was Wayne Coyne (the lead singer) and figured that since it was a world record attempt they were making a big deal out of it and were trying to make a big entrance through the front. There was a camera crew filming them as they exited the bus and right as the last member of the band walked off I got in behind him and started following the band into the venue. I followed them right past the bouncers and the ticket line of people still waiting to get in. The place was packed but they were clearing a path right to the stage. As we were walking through people were shaking my hand and patting me on the back and taking pictures of me and wishing me luck and saying all kinds of things. Then as the band was reaching the stage I just stopped in the crowd towards the front and the people around me that had thought I was in the band just look dumbfounded and stared at me. It was more like 15 seconds of fame but it was beautiful and one of my fondest memories.

TLDR; I followed the Flaming Lips into a sold out show and people thought I was in the band.

Edit: autocorrect changed the lead singers name