Completely insane, bluntly stated, funnily accurate, very subjective, surprisingly universal. This is Life... You can love it, you can hate it. But you can't forget it!!
There is a time in everyone's life when he/she feels bad about life in general and lot of other stuff. We tend to envy "grown-ups" when we are students seeing that they don't have to study and yearn for the student life to be over but when we start working and taking up responsibilities, we wish that we could forever remain students. So, it (i.e. our longing) keeps changing over the years. ]
It's just a matter of time when everything would fall back into place or you might stop caring so much.