When you're so giddy or excited that you start randomly dancing just like the characters from West Side Story while doing everyday things, such as walking to school, opening your locker, brushing your teeth, etc.
Person 1: Hey, why is that guy just randomly dancing?
Person 2: I don't know, he must have West Side Story Syndrome.
Person 1: Yeah, that must be it.
Person 2: I don't know, he must have West Side Story Syndrome.
Person 1: Yeah, that must be it.
by #mexicanfood February 24, 2015