It’s very difficult to “un-know” what we know. This makes it really challenging to communicate effectively. Sometimes is causes us to talk over the heads of our audience when we assume they posses knowledge they don’t. Other times, it means we talk about things that are interesting to us but not necessarily our audience. If this happens during a presentation, you’ll start to see heads nodding or (worst case) a mass exodus.
But if your web site is guilty of this, visitors will simply leave or (worst case) become annoyed enough to share their frustrations with others. That’s why it’s important to understand why people are coming to your site and provide them with 1) the resources they’re looking for 2) in a way that makes it easy to find. Reviewing your website analytics every day is one way to stay on top of traffic patterns and understand where people are going on your site.
If I’m not articulating my point well enough, maybe this infographic from xkcd will get the point across.