Part of it also is being ready for the knowledge and/or having a reason to know something. Often, I'll read something or more likely skim it. At the time, it may not be pertinent. Then something will happen and I will remember having read that. This is where tools like delicious come in, because I save something that may be useful later, but I don't really need now. I make sure that i include notes so I'll be able to find it later.

Even then, I may remember reading something, but can't find the source. The fact is that it just was not relevant at the time. I filtered it out, but not completely.

There are some good organizational communication tools, such as a communication audit, that allows a company to see the ebs and flows of ideas.