A dude in my film class looks like Mika.
I ran in on the first day (I was late), saw him, screamed "IT'S MIKA", hugged him, then looked at him closer and I was like, "OH CRAP< YOU'RE NOT MIKA" and apologised, walked out again, then re-entered and sat down in a dignified manner.
I was so embarrased now my teacher always takes the mick over that 'little' mistake.