If you're like most people, you live almost entirely in your mind. There's a constant internal dialog going on, the mind always talking to itself. "I need to do this...", "What if that...", "Yesterday I...". As soon as one thought is finished, another pops up. This is going on non-stop, so much so that really paying attention to all these thoughts would start to drive you nuts, so all the thinking starts getting pushed into the unconscious where it goes on automatically, habitually.
This is dangerous though, and the fact that nearly everyone else is doing it too doesn't make it any less so. Your thoughts influence enormously how you perceive your world. In new age jargon, this is the "you create your reality". Your beliefs are the lens through which you see the world, though for most, it's more accurate to say your beliefs are your world. To let the mind ramble on unconsciously is very dangerous because it will go on absorbing, and modifying beliefs without any conscious direction from you, and these beliefs will direct your whole life.
When you're unaware of your own thoughts, you're like a leaf blowing in the wind, and it becomes very easy for people to manipulate you. The media can just repeat something over and over again, and whether or not it's true, the majority of people will start repeating it as fact. Most mainstream forms of media, advertisers and politicians have refined manipulating people into an art. They even know the emotional triggers people have that feed into unconsciousness, one of which is sex. Get people a little bit aroused, get the mind excited and it becomes easy to sneak thoughts into them. Other common triggers are things like violence, fear, or the promise of money. If someone can convince your mind that they can fulfill your desires, they can very easily control you.