That may be the reason for the addiction. Gaming is the one thing that takes enough concentration to do well that it takes me away from work mindset or just life in general for a while.
Once I beat a game usually I'm done with it. Games have a built in necessity for skill development, so you have to attain new skills from beginning to end. Most games don't have enough replay value that I'll go through them a second or third time, though there are rare and spectacular exceptions.
