Becoming jaded is part of growing up. Call me a pessimist all you like, but sooner or later, the lofty idealistic nature of youth is forced to confront the hard truths of realism and the inevitability of adulthood.
The first sign that this is taking place is when you begin to utterly despise the perfectly normal albeit infuriatingly annoying behavior of others. To get a better idea of what I'm talking about, have a look below and see as these women of Reddit share at what point they started hating people.