Is Ignorance Indeed Bliss?

I was thinking the other day, about how the idea that the earth was round had been proposed so many centuries ago, yet humanity still chose to socially ignore it and believed that it was in fact flat, with no scientific evidence to reject the claim, just an instinctive feeling that "well, it must be flat, how wouldn't it be?". And this is just an example, one of many popular misconceptions that were challenged, successfully, with the establishment of scientific thought.

It could actually be argued that people back then were much more content believing that there was nothing but the end of the earth beyond those vast oceans, for which they had neither the technology nor the need to examine any further. So, it could be said that, sociologically, it was safer for them to be free of such worries and questions, until they actually had a need for what such research struggles would offer - namely, there were at some point too many people and not enough resources for them, so new land needed to be found. And only then was the truth faced and acknowledged at last.

'Cause up to then, there were already people who were familiar with, say, Pythagoras' theories and calculations, but whole systems were in place to make sure that, socially, nothing like that would be taken seriously by anyone who could research it further or do something about it and still let others know.

So, this makes me wonder: Is there some type of social mechanism that urges humanity to deny certain types of knowlege for which there is no direct need yet? Do people as a whole actually deny certain truths just because they can't be bothered with them right now? Is there a whole set of common dreams and experiences that we could all strive for but don't really need the hassle?

It would make sense that humanity would deny a whole set of areas of research... And what good would it do, for example, to physically locate or scientifically examine the human soul, should it be in any way tangible? Would it cause anything but fears and worries right now? Aren't we better off if we don't ask, until or unless we ever have a reason to?

We still have so many things to worry about, hope and strive for, scientifically. Space travel and colonisation, for example, is a hard enough goal already. It's just that I'm curious to find out what we don't want to find out. Oh well...