I've witnessed a few, some ladies cursing loudly at each other at DL and a kid yelling "I wanna go Home" on the monorail, but my personal story involves my sister as a teenager. It was our first park day and we wanted to hit the ground running...but wait! My sister MUST go through her 3 hour shower/leg shaving routine. Well, she should've gotten up earlier, because the rest of the family just wasn't having it. This became a point of contention, with my sister finally declaring that she will just have to wear pants. In Orlando. In June.
So she did just that and she didn't speak with us for the entire ride over to MK, the walk up Main Street, through the castle and in the line for 20,000 Leagues. But, you know, something happened after that which is what I remember most about all of it. She came off the ride smiling, and laughing, and loving the day despite all the drama. The magic seeped in thankfully. The next day she got up very early to do whatever it is girls do that takes so dang long and we had an incident free trip after that.