If you have a screen door you know it works well for keeping out cold in winter and letting in the nice breeze in the summer time. When people come in the door, they usually just open it and come in and it closes gently by itself. What would happen in one of those big huge profession wrestlers came and grabbed the screen door and pulled so hard on it that the springs are pulled straight and the screws are pulled out of the door frame and the door and the door is pulled out of the hinges? Would anyone else be able to use the door nomally again? This is a good analogy to how cocain works in a person's brain. There are doors called chemical receptors in your brain that receive other chemicals into your brain that make you feel good and happy and satisfied. These feelings come naturally from the things we do in life and are like people going in and out a screen door. The very first time cocain is used, it is like the professional wrestler coming and ripping the door off the hinges. Cocaine gives the brain a huge kick of good and satisfying feelings but they are falsely created by a drug. And it is such a huge kick, that it destroys the receptors for those specific chemicals. The receptors can never be used normally again. Users of cocaine say that they can't feel happy or satisfied with the normal things in life that used to make them feel good. Its because the screen door was ripped off in their brain. And this happens the very first time cocaine is used. This is why it is so important to choose to never even try this drug.