It seems that for many people, growing up is a process more complicated then they're able to handle. Even with time, maturity doesn't seem to be guarenteed.
Examples of this can be easily seen in how people think politically. Let me break it down for you.
Libertarians / Tea partiers - these are the classic emo kids. They think everyone is out to get them, and that no one understands them. Somehow, they believe they live in isolation from the rest of society and they just want to be left alone writing their crappy poetry/shooting off their guns and not be responsible for anything or anyone else. They seems to have a short memory when it comes to where they actually get all their stuff or the freedom that they enjoy. They enjoy being the outcasts, yet they band together in small exclusive groups trying to anti-social (not knowing that by banding together in small exclusive groups, you are being exactly what you supposivley hate). All of their political ideology are based on the world revolving around them.
Republicans - these are the generic immature high school kids. They think they know everything and have a sense of entitlement. They think they know what's best for themselves and for the rest of the world without taking into account anyone's perspective on anything. They think in terms of black or white, right or wrong. As is popular with most kids at this age, they have a sign that says 'keep out' on their bedroom doors without realizing who pays for the bills in the house they live. Being stuck at this maturity level means that they are quick to judge and change their mind with little idea about hypocracy or the big picture.
Democrats - these are the idealist youth who believes that they can save the world and that there is indeed still good in everyone. They believe to a fault that everyone tries to do the right thing and that everyone believes in fairness. Like the Republicans, they too also believe they know everything. They can be naive in their thinking as they don't understand that not everyone has the best intentions. Not everyone believes in the greater good.
As long as we're stuck with these groups in government, there is not that much chance there's going to be any progress in society.