Unless academic achievement in one’s youth is followed by lifelong habits of study and inquiry, it may lull a man into grossly overestimating his understanding of the world.
As far as I know, history’s worst example of this was Nevil Maskelyne, the English Astronomer Royal from 1765 to 1811. A key member of the Board of Longitude during a period when Britain was desperately trying to discover a way to calculate longitude at sea, he was so proud of his knowledge of astronomy and mathematics that he steadfastly refused to acknowledge that John Harrison’s marine chronometer offered a simple, mechanical solution to the problem.
For years, Maskelyne used his influence to prevent Harrison’s chronometer from being recognized as the obvious solution that could prevent British vessels from getting lost at sea and shipwrecked because the navigator couldn’t be sure of his longitude. It was only when Harrison got an audience with King George III—who pronounced “By Jove, Harrison, you’ve been wronged!”—that he was recognized for his ingenious and useful invention.
Nevil Maskelyne was a talented astronomer and mathematician, but when it came to the practical business of easily calculating longitude at sea, he was dead wrong, and his academic pride hindered him from acknowledging it. In addition to terribly wronging John Harrison, Maskelyne consigned innumerable sailors to misery and even death at sea by delaying the widespread adoption Harrison’s chronometer as standard equipment on British vessels.