A bunch of people are wondering 
what blogging is and why they blog -- wondering about rules and mores and Truth. Interesting stuff, which reminds me of a story. Once I took a fascinating graduate-level class on the History and Philosophy of Science.
The instructor was a former PhD biochemist who had gotten a second PhD in philosophy. It was an extraordinary experience for me
to explore the diversity of the epistemology and narrative structure available to philosophers versus scientists. Most of the other students were master's students, or advanced undergraduates, in philosophy. One student
liked to think of himself as belonging to 'continental school' of philosophy. (The other students assured me this simply meant that
his papers didn't have to make any sense). I was the odd-man-out, being a doctoral student with a background in science. One moment that sticks with me was when I explained a realization about realism to
the instructor.
"My brother has this friend," I said. "This guy is a devout Christian who believes that the Bible contains the words of God. But not everything in the Bible is the word of God -- there's a bunch of other stuff mixed up in there too. But that's OK, because this guy can tell which parts are really the words of God and which are not."
The instructor was impressed with my rhetorical style, to create a straw-man to assume an extreme position for the point of argumentation.
"No, no, no!" I said. "My brother really knows this guy!"
I realized only later that this exchange was emblematic of the problems with scientists and philosophers trying to make sense of each other. Philosophers spend a lot of time trying to figure out the line between what could and what could not be. Scientists want to talk about what is (often understanding this is limited to what can be observed). Philosophers talk about what it would mean, if crows are black, to observe a white one. Scientists are used to seeing albinos -- it's not a big deal. There was a lot of this in that class -- it was great.
Near the end of the course, I was chatting with some of the students and the contintental philosopher said, "You know. You're really good at this. You really could be a philosopher." The idea of "being a philosopher" struck me as hysterically funny somehow, and I nearly keeled over laughing. The poor fellow's feelings were terribly hurt. I was actually rather honored, since I understood his remark to be sincere adulation, and I tried to make amends, but I suspect he never really forgave me.
To come full circle, I began blogging when I realized that I was typically writing email to my circle of family and friends and having trouble remembering what I had told one person or another. Sometimes I would copy multiple people on a message, and then want to write something to just one of them. Sometimes, I would start a message and have it run into a topic that I wanted to share more widely. I decided instead to just start writing a journal that would include all the "common" stuff that I would feel comfortable sharing with more-or-less anyone. The idea of making up stuff to put in my blog had never really occurred to me.