I had to quite mathematics and move into philosophy because there was a genius in my linear algebra class.
His father was an engineer and sent him to mathematics camp every year.
His exam scores brought everyone elses down and he wasn't required to attend lectures. (I only saw him once in two semesters).
Found out later that he was bored with mathematics and moved to the theater department. Go figure.
I always hated the kids who ruined the curve. What nerve, too; messing with the curve and not even bothering to show up for class.