Is it normal to be addicted to drop7?

I got the game 'Drop7' for my iPod touch a few months ago and I love it. It is just so simple and addictive. If I'm not in a conversation with someone or occupied with something, I think about tactics for how to win games and am pretty much obsessed with rising my average score. If I don't get a higher score, I quit the game before it ends. IIN?