I've spent a good deal of time thinking about this lately. How grateful I am for trusting parents who didn't immediately rip books like Go Ask Alice out of my hands because the book is "dirty" (which it is), but instead trusted that I would talk with them about what I was reading and use the experiences of others as a way to find more strength in my own belief system.
I mention this because I've seen more often than I ever have before in my life recently the idea that the world is full of dark, evil things and that the best way to keep evil things from corrupting you is to hide from them completely and not explain why to those around you (particularly in the form of parents talking to their children about the world.) For example, I had a friend tell me of an experience she had at school in a class where a girl (high school junior) was convinced that babies grew in the stomach (and wondered why pregnant women didn't have a baby-sized tumor on their side.) She was corrected by another student who said that babies ACTUALLY grow in the small intestine.
But it's not so simple as basic reproductive understanding, either. There's also a great deal of fear for what is out there. I've seen parents terrified of their children finding out about certain lifestyles or reading certain books that talk about what they don't agree with. Not that there isn't a good time and place (and age) for certain bits of information, and there are certainly books that are inappropriate or full of garbage - but it seems to me that those who live in this way don't understand the basic tenants of Mormon faith.
Our church is founded on the idea of learning for yourself. The church itself would not have even been established if Joseph Smith hadn't been curious. If his parents hadn't allowed him to attend other congregations to try and find truth. It seems to me that people who live this way (or parents who force their children to live this way), are afraid that the truth of the gospel will somehow not be strong enough or true enough to stand up to the diverse ideas of the world. Or perhaps these individuals simply think that the LDS faith has a corner on truth and that there are no other means by which truth can be found or expanded on. (For example, I've known my share of people who don't seem to understand that my faith is strengthened through fiction.)
Ultimately, what this leads to is a population of people who breed fear of the unknown. People who take one look at something that is unfamiliar and immediately interpret it as wicked or somehow 'wrong'. They don't want to talk about or try something new because it might be what they fear it to be. To which I say: Yes. It might be. But it might NOT be. It might be something you could actually talk about. You might actually be strengthened by reading/writing about/listening to/watching an idea that is not like one you currently hold. It's no wonder so many people in this valley live in fear - it's easier to assume the worst and refuse to talk about the truth than it is to actually talk openly about things. Bad things happen when people are left to wonder.
As for me, I feel like my life would be not quite worth living if I spent all my time and energy trying to keep bad things out. I'd rather spend my time seeking out good things, because - as we all know - light will always overpower darkness.