Bobblehead
When I was in school, I thought the surest way to learn was to furiously transcribe notes.
This would indicate to everyone around me that I was attentively absorbing every line. And while scribbling I would make sure to occasionally shake my head up and down as if it were mounted on a spring. I felt assured in my growing knowledge base.
But, a spring deforms when put under strain (Hooke's Law). My bobble head brain could not withstand the force of serious critical thinking. It remained bent out of shape until I discarded it along with the head that had a penchant to nod yes.
Now when I did not comprehend the topic at hand, I could stop and ask questions.