When you don't study for an exam, but still pass

I had it since i was a kid. I never study for exams, and I pass them easily most of the time. I have it since i was a kid. I always never try to study for exams, yet I pass them. But I know I may have to study someday. I feel like I'm cheating the system, and I'm not doing anything right. But I still pass with good grades. But I still feel like I'm cheating. Any thoughts on this?