Roger Rosenblatt's written a really interesting article in TIME's January 29, 2001 issue. The subject is marginalia, and the way people are always commenting and noting things, internally or otherwise; the concept that nothing is final.

Every thought breeds an internal commentary, a counterthought (not always), some elaboration on the initial matter. Every action taken incurs an inner comment. (Every action?) Everything we are is under continual revision. We even live in the margins of one another's lives. (Prove it!)
Besides for the article itself being very interesting, Rosenblatt has also marked it up with notes, these I have (parenthesised and underlined).

And this is what I have decided - E2 is not a BBS, nor is it a database, nor is it a community. No, it is none of these but all together, and it is one mass documentation of marginalia. We read nodes, and go Hrmph... What is softlinking, if not our own little jotting down of ideas?

...Friends would deliberately lend Coleridge their books, knowing he would mark them up endlessly. Thus, the lenders would be getting back a book improved by Coleridge.

...Other writers were known for their relentless annotations too... but quality that high is rare. We take a book out of the library, and read the marginalia, often surly and stupid, of anonymous strangers. (Thanks a heap!) The fun, though, is to respond to them, by which we perpetuate the argument and extend the text. (Back to the thesis, at last?)

Or, one can simply respond to the language and doodle: thesis, Croesus, Jesus. (Jesus!)

And this is more of Everything. The arguments, the give and take. The essays, noded from multiple perspectives, the nodeshell challenges, Everything. It's all marginalia, and I like it. Because this is the way our minds work, and this is documentation of it, and this is people and more people marking up the text of our lives.