They don't wonder it at all; it's not some mystery solved by sitting in a classroom. Adolescents, as a demographic, have always been known to be raging pits of hormones with mood swings and strong passions. Items 1 and 3 are common in the working world, and there's a few jobs out there as a 2 as well (particularly if you focus on the 'lack of autonomy' part), yet we don't see the same kinds of behaviour from those workers.
Adolescence is a time where you're finally becoming an adult, finding where the boundaries are, and putting your own flavour on life. There's a certain amount of experimentation with that, and it's entirely normal to have more unruliness amongst adolescents.