I know very little as well, but did my research before purchasing and talked to a lot of folks. Not an elegant analogy, but why does someone need to own a Lamborghini that can go 200 mph (and pay $400,000) for it? I know a few guys that own them and I've shot one at the range. One of them is a collector and one likes the feel of firing it occasionally at the range. Another guy is ex-military. And I'm sure there are people that think that they want to be better armed than any bad guy that will ever show up at their door. I think the mistake most non-owners make is that they group all gun owners in a one demographic.
I agree that if you want to be ignorant about the motivation to own guns, watch cable news. I have found most gun owners more than willing to talk about their interest, none of which I can say that I walked away from thinking, "Jeez, they shouldn't own a gun!"