It was pretty clearly a lie of omission when I didn't correct the teacher, so eight-year-old me felt guilty for that.

Why didn't I? Partly, because I couldn't muster the courage, and partly because she'd gone on in the next sentence to use my "hard work" as an example for the class and I didn't want to undermine the lesson.

Now, adult me can look back and say, "Kid, there was no need to feel any guilt; what you did was fine given the situation and pressures." But that precocious third-grader knew Lying Was Wrong.

It's about the difference between honor and reputation.

Reputation is what other people know about you. Honor is what you know about yourself. The friction tends to arise when the two are not the same.

Lois Bujold, "A Civil Campaign"