I have similar experiences with my DS8 who is in 4th grade (skipped K, PG, maxes out the tests they give him). He complains to us sometimes if he is bored in math. In all other subjects he usually just does what is asked of him - he's a rule follower. This has made it particularly difficult when asking for differentiation, because the teachers expect him to be selecting harder work or demonstrating boredness.
When we quiz him about it, he will eventually admit that he is bored and wishes he were more challenged. We talk to him a lot about challenging himself when the opportunities arise (pick a harder book next time!) and about how his choices can impact my ability to advocate for him to get the harder work he wants.
But, ultimately, we seek a balance: strong work ethic, having fun, being a kid, liking school, having friends, being challenged, learning, building skills, pushing oneself, being obedient, speaking up for yourself, doing one's best, effort over achievement... I am trying to build a whole person here and that development comes from so many different places. That's the thought that helps keep me moving forward, anyway.
