In high school, I belonged to the so-called "star section". We are a group of students who are deemed as the batch's brightest students and are, in theory, most likely to succeed. Getting into the class is difficult, as well as staying in it for the whole 4 year experience. I had to study hard just to stay in the class, as I know for myself I'm not naturally smart unlike most of the people in my class. During my sophomore year, I was dispelled from the star class for slacking off in my studies and was placed in the "lower class". I eventually managed to get back in during my Junior year after a full year of hard studying and staying away from my classmates.

So during graduation, 3-4 kids from each of the lower class was not able to graduate to their incredibly low marks. They would have to repeat their last year in high school. I didn't pity them at all. I reminded myself how hard I worked just to maintain a good grade. Why can't they do the same to save their studies? But there's something more I've felt... I wasn't just unfeeling towards the fall of some of my batchmates. I was HAPPY that I made it and they didn't. I felt glad that my works paid off and the slackers from my batch got what they deserved.

Am I a terrible person? ... Any advise?

You're probably a sociopath, and possibly a serial killer in the making. Get help now. Before you start murdering and raping small children.