Cheating

So I caught a student cheating during an exam yesterday. Great. Just what I wanted. It resulted in twice as much work for me, a giant interruption for the other kids trying to take their exam in the same room and a huge amount of stress for the kid that got caught. What I don't get is why he thought it would be worthwhile to cheat on about 12 words (I picked up a small square of paper, maybe 2cm wide, with a list of about 12 words on it). Really, it couldn't have helped him with more then about 5 points on the exam, and now instead he will probably get a zero (unless there is some loophole that I left open by not knowing the necessary process). I guess I really am an optimist because the entire time I was going to see if what I saw was real I just kept thinking, "no, he wouldn't be cheating that obviously. He's a good kid, why would he cheat?" Although when I picked up a piece of paper he tried to cover up with German words on it I felt it became pretty obvious. The question is what makes a good kid (one who is normally in my top 5 in this particular class for math) get to the point where it was worth damaging his integrity? Admittedly exams are not the easiest time of year, and grades here seem to possess and even greater importance then they do at home. It's just sad that this kid is now going to have to live with the knowledge that he didn't trust in himself enough to take an exam on his own. Sigh.