[Natsu]

The test for obviousness is... less than robust. In a quest for legal certainty, "obviousness" is tested by applying the teaching-suggestion-motivation (TSM) test[1]. While this does help to prevent hindsight bias, the fact is that people often fail to state the obvious, so there may be no record of just how obvious something was. So blindingly obvious things can and do slip through, though the Supreme Court has tried to give the courts some leeway to strike down the worst of the lot with KSR v. Teleflex (2006).

[1] https://en.wikipedia.org/wiki/Inventive_step_and_non-obvious...