Most embarassing:

I had to interview at my uni for my place. I'm not the most extroverted person out there, and I arrived for my interview a day before most other people applying for my subject, and a day after the people there for the other subjects. So when I showed up, there were already a few groups that got on well, and I was a bit too scared to break into any of them, so I sat in the common room alone hoping someone would say hi.

Later on in the evening a student rep walked in and said there'd be a film playing in the auditorium, and that for anyone who wanted to watch it there'd be another rep who'd come in in a few minutes and stand by the door, and people should follow that rep.

I wasn't talking to anyone so I figured a movie was the best use of my time, so when a rep walked in and stood by the door, I went over and waited there with a number of other interviewees. We then went out and the rep led us through the compound until we were walking out into the street. I thought it was a bit odd, but I knew there were buildings a little way off, too, so I didn't think about it much.

Then we got onto a bigger street, a main street, and then everyone else, who I'd slowly begun to realise were all getting on very well, started discussing which bars to go to. As we turned into a bar it suddenly dawned on me that I'd accidentally got caught up with a group of friends who knew each other from elsewhere and were just going out for a drink together, and I was this guy that none of them knew who'd just tagged along.

I put an emergency plan into action and started talking to one of the quieter ones. Fortunately he assumed someone else had invited me, and that meant that afterwards everyone I could ambiguously say I was "getting on" with the quieter guy so people would think he invited me, and I just heckin bamboozled my way out of that one.

Not before a long period of odd stares and whispered "who's that?" though.