1 stick of cigarette kills 4 neurons of your brain.

Neurons are the cells in your brain that are responsible for its vital function. Neurons don't regenerate. Meaning they don't grow back. So QUIT SMOKING.

TIPS HOW TO QUIT SMOKING
1. If you're determined enough to quit, then that's all you need. Your WILL.
2. If you can't quit at once then try it gradually. How? If you finish 6 sticks a day, try decreasing 1 stick at least 2-3 times a day and replace the missing ones with candy or gum. Whenever you feel the urge to smoke always remember to bring a candy or gum in your pocket and forget to bring those cigarettes.