The thing about life is that you can't control what happens to you, but you can control your reactions to it. You may be faced with adversity, uncomfortable situations, rude people, bad encounters, etc. Those are things you cannot control because they are outside you and not part of you.
However, how you react to them is what matters. That is the only thing you have under your control. Whether you will be angry or reasonable, whether you will walk away or confront the situation. You control your reactions.
If you are not able to control your thoughts, they will control you. You will become a slave to them and your life will be governed by what you allow in your mind. If you are negative towards everything and your thoughts only belittle you, your life will not be fulfilling.
However, if you take control of your thoughts and turn all the negative thoughts into positive ones, your outlook on life will change. You will be able to view things more positively, be gentle with yourself, and even believe in your capabilities.
You need to be able to take control of your life. Have a say in what you want. Let your opinions be heard. Tell those around you what you need. If you don't control your life, someone else will. Someone else will decide for you what to wear, the things you should do, how to act, etc.
You should also control your words. The things you say have the power to build your life, destroy it, and do the same to other people too. Here is a collection of control quotes to give you more insight. Remember, you should never let what's beyond your control affect the things you can control. Control what you can and allow everything else to fall into place.