TBBT 4A Apartment.
"What?"
Howard froze.
"Just like geography, which isn't a science, Sheldon was very interested in engineering for a time when he was in college, until he met an arrogant tenured engineering professor."
Adam explained with a smile, "He kept tearing up Sheldon's assignments without ever pointing out what was wrong. He just kept tearing them up and making Sheldon redo them. From then on, engineering sank to the same level as geography."
"Oh, honey."
Penny immediately looked at Sheldon with sympathy. "I never expected you to have gone through that too."
"I'm not like you."
Sheldon disliked Penny's expression, as though they were somehow the same.
"It looks the same to me."
Penny was delighted.
It was rare to see the incredibly smug Sheldon fail so badly at schoolwork. She was thrilled.
"Don't make that face!"
Sheldon snapped.
That tenured engineering professor had always been expressionless, until Sheldon had been tormented so badly that he couldn't sleep soundly. Then, after he was late and locked out of the classroom, Sheldon saw that awful man make that same hateful expression.
And when Sheldon tried to go to the principal to complain again, he discovered that the principal had made that awful man imitate Sheldon's expression when he was locked outside the door, and the two of them had burst out laughing.
"So that's why you've always hated engineering and kept attacking me?"
Howard suddenly found it a little easier to accept.
"No."
Sheldon looked at Howard. "At first, it really was because of engineering. After that, it was entirely because of you as a person."
"Forget it!"
Howard waved a hand. "This ends here. I'm never stupidly taking one of your classes again and letting you get revenge!"
"Don't be sad."
Bernadette agreed as she stroked Howard reassuringly.