When I was in 5th grade, I cheated on a test. I didn't know the answer to one of the questions, and I wanted to get a good grade, so I looked at my classmate's test and got the answer. Wouldn't you know, I got a 100 on that test. Well, it bothered me so badly afterwards, especially with getting a 100, that I stayed in at recess time and "confessed" to my teacher, whom I happened to have much respect for. In fact, many times I accidentally slipped and called him "Dad" when addressing him. He thought I was very brave for coming forward with this. He talked to me about right and wrong, and allowed me to keep the grade.
Many years later, when my own children were going through the same school district, I approached this teacher and he remembered me and the incident. He said out of all of his years teaching, he never had a student come forward and confess to cheating.