Why Even Bother?

In my statistics class today, a guy answered his phone during the lecture. This is not a big class, only about 25 or 30 people, yet he sat there talking and laughing on his cell. It was so rude and obnoxious. Of course, my poor, little, Polish teacher is too quiet and insecure to have said anything. The same guy left class around 45 minutes early. I just don't get it. Why did he even bother coming at all? People like that really bug me. They take nothing seriously and have no ambition. They all could use a slap in the face to bring them into reality. And do their parents realize they're paying for their son/daughter to skip class and party all the time? I guess not.