Addiction

We are addictive by nature.
Its pretty easy to find something you are addicted to in your life, be it physically or psychologically.
Cigarettes and heroin can give us a physical dependency.
Whats also dangerous is that other substances, like marijuana and coffee can be psychologically addictive, as the user is addicted to the way it makes them feel.
I was a heavy pot smoker for a good 5 years of my life, and it was quite hard to kick. I never had any severe withdrawal symptoms, but after being stoned for so long, it becomes your normal state, and literally I was smoking at one point just to feel normal.

Its not only substances that can be addictive. I've seen it often enough where people are addicted to a feeling, an emotion.
Sometimes its being in love, where someone will let themselves fall for the completely wrong person, based on an allusion of what the person is like. Destructive relationship ensues, and then repeats as the addict loves to feel in love.
Depression can be addictive. Its not unusual to indulge in melancholy, as sometimes just to feel something, anything, can be better than feeling nothing at all.

Anger is an interesting one. So prevalent in our society it is, and the cause of all our wars, our murders, and most of our pain.
A common psychological misconception is that if we don't release our anger, that it will come out in other ways (e.g. 'Me Myself and Irene').
The truth is, releasing anger, be it hitting a punchbag, yelling at a subordinate, or killing a hundred people in a game of counterstrike, makes you feel good.
When you do something that feels good, you want to repeat it .
Its what we are.
Addictive.
When we feel that release of anger, and the rush we get, its addictive, and we crave more, so we become prone to getting angry a lot more.
If you learn to control your anger, it fades to nothing. You can focus more on other tasks that are more important in life.
As I've found.