In a general sense, anything can sit around undetected doing its thing, until it is "discovered".
Diseases operate by a mechanism even if we don't necessary know exactly what is going on.
Thus, a key component of discovery is "entering consciousness". There is also the matter of "first time". The thing is, people die....so their memories go with them. If a new generation comes to fruition, they will never know the day-to-day nuts and bolts of the old days....
J.S Bach fell out of public consciousness, leaving it only to a select individuals with the resources to have access to hold the scores (Baron von Sweiten). Then the community of musicians who make contact with said elect individuals can then hear, play, and learn from the music, such as Mozart. Thus, though Bach played for minds during his time, a new generation of minds like Mozart DID NOT really hear the and studied the music of J.S Bach until the early 1780s, even WITH contact with the sons of Bach.
The general public would not rediscover Bach until the work of Mendelssohn.
In actuality, Christopher Columbus has been irrelevant in Anglo society for hundreds of years....quite a few wars, revolutions, etc, made him a historical figure known only in books even mere decades after his time.
The argument of who first discovered the Americas ultimately boils down to semantics of what sense of "first time entering consciousness" is being used.
Columbus' landing and return was the trip in which the Americas did not wind up forgotten afterwards...so far...
Also, the simple-mindedness and quasi-religious fervor of the American masses to masturbate themselves mentally really is in full display, as evidenced by the ignorance of the lobbying process to even get a federal holiday. Columbus Day was a minority-lobbied holiday due to racism against the Italian-Americans; this is why even the likes of Cuomo will go to those parades, because that holiday is relevant to them...but no one else can relate. Last I checked, there were many Native American nations formed during the 1800s. If Americans really want to wind things back...they can lobby to start ceding land and gradually shrink until everyone is back to their old continents.