"It is the patentability standard of obviousness—the legal
framework upon which courts and the Patent Office interpret whether the proposed
invention would have been obvious to a person of ordinary skill in the art—that
controls this balance. The difficulty
for courts in determining obviousness, and thus patentability, is hindsight
bias. When someone already knows how an
invention works it is all too easy to consider it obvious, yet before learning
about the invention, the same person would not have been able to envision the
invention."
(Scott R. Conley, Irrational Behavior, Hindsight, and Patentability: Balancing the "Obvious to Try" Test with Unexpected Results, IDEA Vol. 51 No.2)