Ignorance is the inherent source of fear not bliss.
Many fear the darkness because hides the world from our sight.
Ancient cartographers filled the seas with monsters becuase they did not know what might exists beyond the bounds of knowledge.
People seek knowledge because with it comes freedom from irrational fear.
However, within the condition that ignorance is in fact bliss no rational answer exists.
Well said.
People who claim ignorance is bliss are doing so from a short-term perspective. As one's doubt in something grows they will often create their own shadows that would plague them if they ventured into the unknown. This, of course, depends on the circumstances, and seen as how there are endless possibilities, I won't go into them. This time period between bliss and fear could be days...it could be generations. Fabricated fears hinder people from looking forward, and I suppose in that sense, ignorance could be bliss--it's better to not know something than to awaken the unknown that could come from it.
Ignorance gives a sense of bliss, but it's false. Only by knowing are you able to truly fear something for what it is...or to enjoy something for the same reason.