I'm with @Wrecky that worst isn't defined at all here! Is it in regards to law, good vs bad, experiences, other, all? I'm running with what comes to mind. The worst thing I did was leave my camera on a counter after buying a drink in Monaco. When I went back it was gone and so were a months worth of trip photos.
I honestly think most people are not even aware of the worst thing they have ever done, since it often involves others who never express themselves.
Ok in respect to you being so honest.. lol I once trapped a co-worker in the staff bathroom. I piled crates of beer in front of the door so she could not get out and it was a VERY loud night so no one knew she was there. The other staff just assumed the crates were in front of the door for storage and used the other bathroom. They also just assumed she walked off her shift. I said nothing and she wasn't discovered until closing. I'm sure this isn't the worst thing I've ever done but it definitely wasn't in team spirit. In my own defence she was really in my way, and I was only 19. The perfect age for shenanigans
@Wrecky Exactly! I was about that age. Just old enough to show authority, but still young enough to cause some shit!
My friends and I trolled two guilds back in the days of Everquest - we were trying to incite a feature called a Guild War which would make the two guilds able to fight each other anywhere in the world, but instead we caused a civil war-like discussion in one of the guilds and it totally disbanded over it. Whoops. At the time I thought it was the most hilarious thing ever, now I feel maybe a little remorse... but it's one of those experiences I would never take away from myself either. None of this will have any bearing on anyone who doesn't understand guilds in MMOs XD
