People who want to control others are, at the core, consumed with their own fears and projecting them onto others.
We all know what it's like to want to be in control. In some ways, exerting control is an important survival skill. For example, we have every right to be in control of our own bodies and our own lives. Taking control in these cases is empowering and necessary. Controlling behavior in the negative sense comes from a tendency to reach beyond our own boundaries and into the lives of others. Many people do this with the rationalization that they are helping. This can happen with parents who are still trying to force their grown children into behaving in ways that they find acceptable. It can also happen when people try to control their partners' behavior. If you have control issues, you will see that in one or more areas of your life, you feel the need to interfere with what is happening rather than just allowing events to unfold.
Almost everyone has at least one situation or relationship in which they try to exert control. This often happens because someone's behavior makes us uncomfortable. We may feel it makes us look bad, or it embarrasses us. For example, if your best friend tends to drink too much, you might spend an entire party just trying to prevent her from doing so. This is different from directly confronting her about the problem and allowing her to decide what she should do. Controlling behavior generally goes hand in hand with an unwillingness to be direct about what you want, as well as an inability to let go and let people live their own lives. If you are the one that is controlling, it's probably because you feel as if you are out of control and it scares you. Try to pick one thing you could just let unfold without any control on your part. Examine how it made you feel both before and after, and examine why you wanted to control the situation.
It is hard sometimes to allow others to be who they are, especially if we feel we know what's best for them and we see them making choices we wouldn't make. However, if we are to be respectful and truly loving, we have to let people go, trusting that they will find their own way in their own time and understanding that it is their life to live. Just reminding yourself that the only life you have to live is your own is the first step to letting go.