No doubt one of them was the one who asked his class to write an essay on Keats, whereupon one inattentive student declared that he couldn't - he didn't know what they were.

Rather like the literary man who asked an acquaintance it he liked Kipling.
"I don't know," replied the acquaintance, "I've never kippled."
"Ah, No!" rejoined the literary man, "It's Rudyard Kipling."
His companion answered "I don't doubt it!"