Lisa falls for her substitute teacher, Mr. Bergstrom (Dustin Hoffman) and his unconventional teaching style.
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The Simpsons Season 2 Episode 19 Quotes

Ralph: What's Lyme Disease?
Principal Skinner: I'll field that one. Lyme disease is spread by small parasites called ticks. When a diseased tick attaches itself to you, it begins sucking your blood. Malignant spirochetes infect your bloodstream, eventually spreading to your spinal fluid and on into the brain.
Miss Hoover: The Brain? Oh dear god!

Miss Hoover: You see, class, my Lyme Disease turned out to be (Spells on blackboard) psychosomatic.
Ralph: Does that mean you're crazy?
Janey: No, that means she was faking it.
Miss Hoover: No, actually, it was a little of both.