Although you are clever, it is precisely because of this that you love to be clever, so you sometimes slack off in your studies. ...
You know your little problem, so in your heart, sometimes you worry about being warned by the teacher ... (dreaming of the physics teacher)
Voiceover:
Why do you dream of a physics teacher instead of other teachers?
This actually means that although the physics teacher is also strict, on the whole, he is easy-going and blends in with you, making it easier for you to accept (after being warned) ...