I'm doing an on-going project of digitizing more than fifteen years of long-hand notes. (If you're interested, let me know: I think I've come up with a pretty efficient and effective workflow on how to do this.) Much of it, as you might expect, is more than a decade of notes tied to TPM - a mix of reporting, brainstorming, business planning, budgeting and a whole bunch of other stuff. But I was just scanning a notebook from early 1999. And it's a curious mix of notes for reporting I was doing on the Lewinsky trial for Salon and notes I was taking planning out the structure of the remaining chapters of my dissertation.
On one page will be a sprawl of notes of impressions watching the proceedings, quotes from sources, notes to myself about who the sources are, ground rules agreed to. Then the next page will be chapter outlines. Sometimes they invade each others pages. Usually it's dissertation planning invading my reporting notes. Occasionally, it's the opposite. But it's usually the first because my reporting was already supplanting my thinking about history and Indians and English settlers in the 17th century.