Passage Summary: A professor felt like a total wreck while teaching after pulling an all-nighter, but her students couldn't actually tell the difference between her tired classes and her rested ones.

Reasoning: A professor felt significantly impaired (humorless, exhausted, unable to concentrate) after no sleep, but her students were unable to distinguish those lectures from her normal ones.

Analysis: This 'Most Strongly Supported' question highlights the discrepancy between internal experience and external perception. The professor's subjective feeling of being 'worn out and humorless' did not translate into an obvious change in her performance that students could detect. This suggests that the internal symptoms of sleep deprivation are not always apparent to an audience. Look for an inference that stays close to this contrast—specifically, that one's own perception of their performance while tired may be much worse than how others see it.